Seat spring assembly

Abstract

A seat spring assembly comprising a plurality of main springs mounted at their ends on a frame so that they are in a transversely spaced relation. Each of the springs has an intermediate body portion and end portions which are formed with pairs of torsion bars for imparting yieldability to the spring. A plurality of tie wires extend crisscross fashion across the springs and cooperate with the springs to form a seating deck. The tie wires have portions that are parallel to and adjacent the body portions of the springs and clips connect the parallel portions of the tie wires and the springs. The tie wires thus function to confine movement of the springs to directions in which they resist load. In addition, the tie wires bridge the spaces between the straight portions of the springs and connect the springs so that the springs function together as a spring deck. In one form of the invention, the tie wires are straight and the spring body portions are zigzag, and in another form these shapes are the reverse.

Description

SUMMARY OF THE INVENTION.

Linear springs, as contrasted with coil springs, are commonly used on seating frames such as those for chairs and sofas. When so used, the principal objective of the linear springs is to accomplish a yieldable resistance to load that utilizes a minimum of spring wire while also providing a firm resistance to load. A variety of spring assemblies have been designed in the past to achieve these general purposes. The principal object of the present invention is to provide an improved spring assembly which accomplishes these general purposes in an improved manner.

The spring assembly of this invention consists of a plurality of side-by-side linear or main springs each of which is mounted at its ends on spring retainers carried by the seating frame so that the ends of the spring are firmly held in non-rotatable positions. A plurality of tie wires extend across the main springs so as to form, with the springs, a seating deck. The springs and tie wires are formed so they are parallel at points where they intersect. The intersecting points are clipped together so that the tie wires function to connect the springs and confine movement of the springs to up and down directions. In addition, the tie wires reduce the size of the openings between the springs.

In one form of the invention, the tie wires are straight and the main spring body portions are zigzag to provide for the wires and springs being parallel where they intersect. In a second form of the invention, the spring body portions are straight and the tie wires are zigzag to achieve the same result.

In a hard edge seat environment, the seat spring assembly of this invention consists of only the main springs and tie wires mounted on a frame. In a spring edge seat environment, a border wire and uplift springs are added. The border wire is mounted on the main springs and the tie wires so that a portion of the border wire is disposed above the main springs at one end of the frame. Uplift springs are secured at one of their ends to the border wire and are firmly mounted at their opposite ends on torsion bars in the main springs. The uplift springs and the border wire thus function to provide increased load support at one end of the spring assembly. This end of the spring assembly forms the front edge of the seat which usually accommodates a pillow.

Thus, the main springs, tie wires, border wire, and uplift springs cooperate to provide the desired firm resistance to seating load with a minimum of wire requirements. This advantageous result is obtainable by virtue of the cooperative arrangement between the spring assembly components and the use of tie wires to perform the double function of spanning the spaces between the main springs and confining the direction of movement of the main springs to the direction of the load.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIG. 1 is a perspective view of one form of the spring assembly of this invention shown in assembly relation with a seating frame;

FIG. 2 is an enlarged longitudinal sectional view of the spring assembly and frame shown in FIG. 1, as seen from the line 2--2 in FIG. 1;

FIG. 3 is a perspective view, like FIG. 1, showing a second form of the seat spring assembly of this invention; and

FIG. 4 is an enlarged longitudinal sectional view as seen from the line 4--4 in FIG. 3.

With reference to the drawing, one form of the seat spring assembly of this invention, indicated generally at 10, is illustrated in FIG. 1 mounted on a supporting frame 12 which constitutes a portion of the frame for a chair, sofa, or the like. The frame 12 consists of a front rail 14, a rear rail 16, and side rails 18.

The spring assembly 10 consists of a plurality of main linear springs 20 disposed side by side in a substantially parallel relation on the frame 12. A plurality of mounting brackets 22, of conventional form, are mounted on the front and rear rails 14 and 16 for supporting the main springs 20. As shown in FIG. 2, each bracket 22 has a main body portion 24 secured to the top side of the rail and an upwardly curved retainer portion 26 which is disposed adjacent the inner side 28 of the rail for a purpose to appear presently.

Each main spring 20 has an elongated intermediate body portion 30 which is long enough to comprise the major portion of the length of the spring 20, the portion 30 consisting of a straight length of wire. At its rear end, the portion 30 is connected to a zigzag section 32 and at its front end to a similar zigzag section 34. The rear zigzag section 32 comprises an inner torsion bar 36 and a rearwardly spaced torsion bar 38 mounted in the retainer portion 26 of a bracket 22. A downwardly extending foot 40, integral with the torsion bar 38, engages the inner side 28 of the rear rail 16 to prevent the torsion bar 38 from pivoting in the retainer portion 26. As used herein, the term "zigzag" means a shape having sections that are at substantially right angles relative to each other.

The front zigzag section 34 consists of inner and outer torsion bars 42 and 44, respectively, and a connecting bar 46 which extends between the bars 42 and 44. A forwardly extending arm 48, integral with the torsion bar 44, terminates in a torsion bar 50 which is supported in the retainer portion 26 of a bracket 22 on the front frame rail 14. A downwardly extending foot 52, integral with the torsion bar 50, engages the front side 28 of the front rail 14 to prevent the torsion bar 50 from rotating in the retainer portion 26.

It can thus be seen that each main spring 20 has its end torsion bars 38 and 50 mounted on the frame rails 16 and 14, respectively, so that the torsion bars cannot rotate but are free to twist so as to yieldably resist loads applied to the spring 20. Similarly, the torsion bars 36, 42 and 44 can twist to accommodate yieldable downward movement of the spring 20 to resist loads. The formation of the major portion 30 of the spring 20 in straight form materially reduces the amount of wire that would otherwise be required to form the spring 20.

As shown in FIG. 1, the springs 20 are arranged in a substantially parallel spaced relation. A plurality of tie wires 52, illustrated as being two in number, are connected to and extended between the spring intermediate portions 30 so as to confine movement of the spring portions 30 to up and down directions. Each tie wire 52 is of zigzag shape having portions 54 which are parallel to and adjacent the spring intermediate portions 30. Clips 56, of conventional construction, connect the spring and tie wire portions 30 and 54.

Each of the tie wires 52 terminates in end portions 58 which are substantially parallel to the portions 54 and to the spring portions 30. The end portions 58 are disposed transversely outwardly of the main springs 30 at positions above the frame rails 18. A border wire 60 having side portions 62 and an end portion 64 has its side portions 62 positioned parallel to and adjacent the tie wire portions 58. Clips 56 are utilized to connect the border wire side portions 62 to the tie wire end portions 58.

Each border wire side portion 62 terminates at its rear end in an inwardly directed foot 66 which is secured by a clip 56 to a main spring torsion bar 36. The front portion 64 of the border wire 60 is disposed above the front frame rail 14 and is maintained in this position by a plurality of uplift springs 68 which correspond in number to the number of main springs 20. Each uplift spring 68 has an upwardly and forwardly inclined body portion 70 which terminates at its upper end in a foot 72 secured by a clip 56 to the border wire portion 64. At its rear end, the body portion 70 is integral with a transversely extending torsion bar 74 which is disposed adjacent and is secured by a clip 56 to the torsion bar 42 in a main spring 20. The torsion bar 74 is positively prevented from rotating in its connecting clip 56 by a foot 76 which is formed integral with the torsion bar 74 and is secured by a clip 56 to a connecting bar 46 on a main spring 20. Thus, the uplift springs 68 maintain the border wire end portion 64 in an upper position when the spring assembly 10 is not under load. When the spring assembly is loaded, the torsion bars 74 in the uplift springs 68 yieldably resist downward movement of the border wire end portion 64 toward the front frame rail 14.

Thus, the form of this invention shown in FIGS. 1 and 2 provides a spring assembly 10 consisting of main springs 20, tie wires 52, a border wire 60, and uplift springs 68. The main springs 20 cooperate principally with the tie wires 52, but to some extent also with the border wire 60, to form a spring deck which extends between the rails 14 and 16 and is operable to yieldably resist seating loads. By virtue of the fact that each main spring 20 is formed over the majority portion of its length as a straight wire section 30, the main springs 20 can be economically manufactured from a minimum amount of wire. In addition, the straight configuration of major portions of the main springs 20 facilitates their assembly with the tie wires 52. A soft edge on the front of the spring assembly 10 is provided by the uplift springs 56 which are readily connected to the main springs 20 by virtue of the location of the torsion bars 42 in the main springs 20.

The form of the seat spring assembly shown in FIGS. 3 and 4, indicated generally at 10a, is similar to the form just described. Accordingly, like numerals are used to indicate like parts in the assemblies and only the features which distinguish assembly 10a from assembly 10 will be described in detail. In the assembly 10a, the body portions 30a of the main springs 20a are of zigzag shape, having torsion bars 80 and a connecting bar 82. The tie wires 84 are straight and are disposed parallel to and adjacent the torsion bars 80. Clips 86 connect the wires 84 to the bars 80.

The assembly 10a is an adaptation of this invention to a hard edge seat environment. Accordingly, the border wire and uplift springs used in assembly 10 are omitted from assembly 10a. However, it is to be understood that the border wire and uplift springs can be combined with the main springs 20a and tie wires 84 to form a soft edge seat and the springs 20 and tie wires 52 can be used in a hard edge seat.

Claims

What is claimed is:

1. For use with a pair of spaced frame rails, a seat spring assembly comprising a plurality of transversely spaced main springs extending longitudinally between said rails, said main springs including means at the ends thereof for securing said springs to said rails, each of said springs having an intermediate body portion and end portions at least one of which is of zigzag shape, said intermediate body portion being comprised at least partially of a straight length of wire extending lengthwise of said spring, a plurality of tie wires connected to and extending between said intermediate body portions of said main springs, said tie wires extending generally perpendicular to said main springs and being spaced apart in a direction lengthwise of said springs, each of said tie wires including portions parallel to and adjacent said spring intermediate portions, clip means connecting said parallel tie wire and spring portions, said springs and tie wires being provided in sufficient numbers to form a spring deck which can be conventionally padded to provide a seating surface, said zigzag shape end portion including a pair of torsion bars and a connecting bar extending therebetween, a border wire having side portions parallel to said main spring intermediate portions and an end portion spaced above said zigzag spring end portions and extending between said side portions, and a plurality of uplift springs, each of said uplift springs being secured at one end to said border wire end portion and having a torsion bar at the opposite end affixed to a torsion bar on one of said main springs.

2. A seat spring assembly according to claim 1 wherein said spring body portions are straight and said tie wires are zigzag shape.

3. A seat spring assembly according to claim 1 further including extensions on said tie wires connected to and supporting said border wire side portions.

4. A seat spring assembly according to claim 1 wherein at least some of said springs have a second end portion which also includes a pair of torsion bars, said border wire side portions having transverse extensions located adjacent and secured to some of said last mentioned torsion bars.

5. A seat spring assembly according to claim 1 further including an extension on each of said uplift springs attached to one of said connecting bars to thereby hold said uplift spring torsion bars against rotation during loading of said uplift springs.