IMPROVED COIL SPRING UNIT AND ASSEMBLY

Abstract: Innerspring unit assemblies comprising an arrangement of coil springs in rows and columns are improved by replacing traditional coil springs with triple offset coil springs in an optimum arrangement. The triple offset coil springs are arranged such that a high coil density is maintained to ensure a high degree of firmness while adequate clearance is provided between the columns such that spring squeaking and/or clicking is avoided. Terminal convolutions defined by traditional coil springs are improved such that the terminal convolutions (10) of the present invention define first, second and third offset segments. The first (12), second (14) and third (16) offset segments of the present invention are disposed substantially in a plane. The third offset segments (16) are formed between the first (12) and second (14) offset segments by reshaping an arc side defined by the terminal convolutions of traditional coil springs. Improved triple offset coil springs (30) of the present invention offer structural advantages when incorporated into improved innerspring unit assemblies, such as increased firmness and increased clearance between rows. The triple offset coil springs (30) also permit optimal usage of wire at borders as well as within borders.

Description: IMPROVED COIL SPRING UNIT AND ASSEMBLY FIELD OF THE INVENTION This invention relates to a coil spring and assembly. The improved coil spring is for use in an innerspring assembly such as a mattress. BACKGROUND OF THE INVENTION A. Definitions of Terms A "convolution" is a turn of wire encompas¬ sing substantially 360 degrees of arc and generally defining a uniform degree of curvature except in the case of terminal convolutions. A "terminal convolution" is a final turn of wire at an end of a coil spring. Terminal convolutions do not generally define a uniform degree of. curvature. A "coil spring" is a spring comprising a number of convolutions, including a terminal convolution. An "offset segment" is a portion of a terminal convolution, defining a reduced degree of curvature relative to the'uniform degree of curvature of non- terminal convolutions. First and second offset seg¬ ments are disposed in a substantially parallel relation¬ ship. A third offset segment adjoins the first and second offset segments. A "knot side" is a portion of a terminal con- volution, connecting first and second offset segments _. C PI T ^fa ^ WIPG " and disposed substantially parallel to the third offset segment. It includes a knot which connects the begin¬ ning of the terminal convolution to the end of the ter¬ minal convolution. An "arc side" is a portion of a terminal con¬ volution, that has substantially the same degree of curvature as a non-terminal convolution. It is dis¬ posed between a first offset segment and a second offset segment, and disposed substantially opposite and parallel to the knot side. A "triple offset coil spring" is a coil spring which includes three offset segments. A "dimension of width" of a triple offset coil spring is the largest measurement that may be taken from the third offset segment to the knot. A "dimension of width" of a traditional coil spring is the largest measurement that may be taken from the arc side to the knot. ' " A "dimension of length" of a coil spring is the largest measurement that may be taken from the first offset segment to the second offset segment. A "cross helical" is a spiral coil of substan¬ tially lesser cross-section than a coil spring. An "innerspring assembly" is a plurality of coil springs disposed adjacent one another and arranged in a pattern of rows and columns. A "row" is a series of springs where the first offset segments in the series are laced, together with border wire or with second offset segments of a first adjacent row, by a first cross helical; and the second offset segments are laced, together with border wire or with first offset segments of a second adjacent row, by a second cross helical. The cross helicals run along the length of the rows. A "column" is a series of springs running transversely to the rows and to the length of the cross helicals. "Border wire" is laced, together with outer¬ most offset segments or arc sides, by cross helicals at the edges of an innerspring assembly. "Firmness" is a measure of coil spring com- pression versus the applied load. For a given load, a lesser degree of compression indicates a greater degree of firmness. B. Definition Of The Problem Addressed By This Invention Traditional innerspring assemblies for mattres¬ ses and other cushioned items of furniture present prob¬ lems both within and at the borders. The problem posed within the borders is one of providing mattress firmness while reducing mattress noise, such as squeaking and/or clicking. The problem posed at the borders is also one of providing firmness. An innerspring assembly generally includes a plurality of coil springs. Each coil spring includes a plurality of convolutions, including terminal convolu- tions. The springs are arranged in a pattern of rows and columns. The terminal convolutions of the springs each define a first and a second offset segment, dis¬ posed substantially in a plane and substantially op¬ posite and parallel to one another. The terminal con- volutions each further define an arc side and a knot side, disposed substantially in the plane and substan¬ tially opposite and parallel to one another. The coil springs are arranged in the assembly in a pattern of rows and ' Columns, and border wire sur- rounds the assembly at the perimeter adjacent the ter¬ minal convolutions. The springs are interconnected at their respective terminal convolutions by lacing a cross-helical around both a second offset segment defined by a first coil spring and an adjacent first offset segment defined by a second coil spring. The TE SHEET cross helicals extend along the direction of the rows such that all the coil springs in a given row are laced, together with all the coil springs in an adjacent row, by a single cross helical. The coil springs of outer rows are laced, together with border wire, by a cross helical in order to impart firmness to the border. End coil springs in each row together define an outer column. Outer columns extend in a perpendicular direction to the outer rows. The coil springs in the outer rows are oriented so that first or second offset segments are adjacent the border. The coil springs of the outer columns are oriented so that the arc sides of these springs face outward, adjacent the border. The arc sides of the outer column are laced, together with border wire, by a cross helical in order to impart firm¬ ness to the border. The problem encountered within the borders of traditional innerspring assemblies is that the assembly either tends to squeak and/or click in normal use, or else it tends to lack a high degree of firmness. This problem stems partly from the fact that a high coil density must be maintained to impart a high degree of firmness to an innerspring assembly. But when tradi¬ tional coil springs are incorporated into the assembly at otherwise desirable high coil densities, the springs are crowded together and a tendency toward squeaking and/or clicking develops as a result. Another factor that contributes' to this problem is that traditional coil springs have relatively short first and second offset segments in comparison to the width of the springs, and therefore these first and second offset segments permit only limited engagement of cross helical along the length of the rows. The problem encountered at the borders of traditional innerspring assemblies is that firmness is limited both because of limited engagement of cross helical with the offset segments or arc sides of the terminal convolutions adjacent the border wire, and also because of high torque resulting from applied loads at the borders. The engagement of cross helical with offset segments or arc sides adjacent the borders is limited by the geometry of the offset segments or arc sides in relation to the terminal convolution as a whole. At the outer edges of the outermost rows, first or second offset segments are disposed adjacent the border wire. Here, the problem regarding utilization of wire at the border is analogous to the wire utilization problem within the border. Traditional coil springs have rela¬ tively short first and second offset segments in com- parison to the width of the springs, and therefore they permit only limited engagement of cross helical with the terminal convolutions along the length of the border wire. At the outer edges of the outermost, columns, arc sides are disposed adjacent the border wire and there is a similar problem. If the arc sides define a degree of curvature substantially the same as or greater than the uniform degree of curvature defined by non-terminal convolutions, then only small segments of the arc sides are available adjacent the borders to be laced, along with the border wire, by cross helical. Similarly, there are substantial intervals, along the length of the border adjacent the arc sides of the outermost column of springs, where the cross helical cannot en¬ gage portions of the arc sides along with the border wire. Further, the arc sides of traditional coil springs contribute to the dimension of width of the springs, either because of the degree of curvature of the arc sides or because of the angle at which they adjoin the first and second offset segments. For a given load applied to the border, there will be a greater torque on the border wire where the spring ad¬ jacent the border wire has a greater dimension of width. This is because torque is a function of the distance from the central axes of the coil springs to the border. Therefore, it can be seen that the shape of the arc sides of the traditional coil springs contributes to the degree of torque that results from applied loads at the borders of innerspring assemblies. C. Objects Of This Invention One object of this invention is to provide an improved coil spring assembly that maintains presently preferred coil density and firmness while providing sufficient clearance between columns so that spring . squeaking and/or clicking is avoided. Another object of the invention is to provide an improved coil spring assembly of increased firmness within the borders. ■• A further object of this invention is to pro¬ vide an improved coil spring assembly of increased firm- ness at the borders. Still another object of this invention is to provide an improved coil spring which will permit high coil density, optimum utilization of wire, and optimum clearance between adjacent coil springs in an inner- spring assembly. SUMMARY OF THE INVENTION This invention is directed to an improved innerspring assembly and an improved coil spring. The improvement to the coil spring involves reshaping terminal convolutions defined by traditional coil springs. A first aspect of the invention is that arc sides of the traditional coil springs are replaced with third offset segments which are closer to the center line joining the first and second offset seg- -f Rl ments than conventional springs. The ratio of the center segment between the centers of the first and second offsets to the distance from the center of the center segment to the third offset is less than about 2.6. According to this aspect of the invention, the terminal convolutions of the improved springs each de¬ fine three offset segments disposed in a plane. The third offset segments define a lesser degree of curva¬ ture than the uniform degree of curvature defined by non- erminal convolutions. Preferably the ratio of the dimension of width to the dimension of length is less than about 0.4 and most preferably is about 0.4. A second aspect of the invention is that first and second offset segments are lengthened so as to maximize availability for engagement with cross helical. As a result, an increased portion of the terminal, convolutions, relative to the width of the coil springs, can be laced by cross helical. • ' A third aspect of the invention is that the improved coil springs are constructed in length to width ratios which permit the desired clearance between columns of innerspring assemblies, without sacrificing firmness. The improvement to the innerspring assemblies involves the proper spacing and the utilization of triple offset coil springs. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 shows a perspective view of a mat¬ tress incorporating a presently preferred embodiment of an improved innerspring assembly and triple offset coil springs of the present invention. FIGURE 2 shows a schematic plan view of the improved innerspring assembly for a twin mattress, as seen from line 2-2 of FIGURE 1. SUBSTITUTE SHEET OMPI WIPO FIGURE 3 shows a schematic plan view of the improved innerspring assembly of FIGURE 1 for a full mattress. FIGURE 4 shows a schematic plan view of the improved innerspring assembly of FIGURE 1 for a queen mattress. FIGURE 5 shows a schematic plan view of the improved innerspring assembly of FIGURE 1 for a king mattress. FIGURE 6 shows a plan view of a terminal con¬ volution of a triple offset coil spring of a presently preferred embodiment the present invention. FIGURE 7 shows a side elevation view of a triple offset coil spring of a presently preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS An improved innerspring assembly is construc¬ ted from improved coil springs in such a way as to main- tain high coil density, to provide optimal clearance between adjacent springs so that spring squeaking and/or clicking is avoided in normal use, to provide better utilization or wire at critical locations within the assembly and to provide firmness at assembly borders. The improved coil springs are compact, so that tradi¬ tional high coil densities may be maintained in inner¬ spring assemblies while spring noise is eliminated in normal use. The compact springs permit sufficient clearance between adjacent columns so that spring squeaking and/or clicking is avoided. The improved utilization of wire is accomplished by constructing the assembly from improved coil springs designed to engage a greater amount of cross helical per unit area than has heretofore been feasible. Firmness at innerspring unit assembly borders results from the combination of f OMP better wire utilization and the compact nature of the coil springs. The latter is also effective to limit torque upon the border wire. A first improvement of this invention is direc- ted to an innerspring assembly comprising a plurality of coil springs arranged in a pattern of rows and columns. Improved coil springs, i.e., the triple off¬ set coil springs of the present invention, replace the traditional coil springs used in the traditional inner- spring assembly. The triple offset coil springs are arranged sufficiently far apart to ensure that squeak¬ ing and/or clicking resulting from coil spring proximity is avoided. The shape of the triple offset.springs used in the assembly also permits optimal utilization of wire between columns and at borders, as will be ex¬ plained. A second improvement of this invention is directed to a coil spring comprising a terminal con¬ volution: • The terminal convolution of the improved coil spring of the present invention defines first, second and third offset segments and a knot side. The first and second offset segments are disposed in a plane and substantially parallel and opposite to each other. The third offset segment and the knot side are disposed in the plane, preferably substantially at right angles to the first and second offset segments, and substantially parallel to each other. In traditional coil springs, the arc side extends considerably outward from an imaginary central segment which connect the centers of the first and second offsets. In the triple offset coil spring, the third offset segment is formed by shaping the arc side of the traditional spring such that the third offset segment is brought into closer proximity with the cen- tral line. In fact, in accordance with the invention the ratio of the central segment to the segment between SUBSTITUTE SHEET the center of the central segment to the third offset should be more than 2.6 and is preferably about 3.3. Hence, the triple offset coil spring has a more compact structure. This structure has a surprising number of advantages when incorporated in innerspring unit assem¬ blies. The preferred embodiments for the improve¬ ments of the present invention will now be described in detail and with reference to the drawings. FIG. 1 shows a perspective view of a mattress in partial cutaway, incorporating the improved inner¬ spring unit assembly and the triple offset coil springs of the present invention. This mattress is of outstand¬ ing firmness both at and within its borders, and yet it can sustain heavy applied loads without squeaking and/or clicking. These advantages result from the improved innerspring unit assembly and the triple offset coil springs which will be described in greater detail. -• The use and arrangement of triple offset coil springs in the improved innerspring assemblies solves several of the problems addressed by this invention. First, the decreased width of the coil springs permits greater clearance between columns of an innerspring assembly of a given coil density. Further, the third offset segments defined by the terminal convolutions permit longer portions of coil spring wire to be en¬ gaged, along with border wire, by cross helical at the outer borders of innerspring unit assemblies. This results in increased border firmness. Still further, lengthened first and second offset segments, in com¬ bination with reshaped arc sides of traditional coil springs, similarly permit better utilization of wire at critical locations within the innerspring unit. FIGS. 2 through 5 are directed to four pre- ferred embodiments of the improved innerspring assembly. Preferred dimensions between adjacent columns of triple _υs! __ _ , OMPI " -4 - offset spring coils are given in inches. (3.25 inches equal 8.26 cm; 3.50 inches equal 8.89 cm; and 3.625 inches equal 9.21 cm.) These patterns are preferred when triple offset spring coils are used having first offset segments of about 1.50 inches (3.81 cm), second offset segments of about 1.25 inches (3.18 cm) and a width (measured from the arc side to the knot) of about 2.75 inches (6.99 cm). However, other arrangements for improved innerspring unit assemblies comprising improved triple offset coils of different dimensions should be apparent to one skilled in the art. FIG. 2 shows a schematic plan view of a pat¬ tern of rows and columns, as seen from line 2-2 of FIG. 1, for a twin mattress using an innerspring assem- bly of the present invention. The pattern used in this preferred embodiment comprises twenty-two or twenty- four rows and eleven columns of. triple offset coil springs 30. When the pattern includes only twenty-two rows, the triple offset coil springs 30 are disposed within a total area of 36.5 inches (92.71 cm) by 73.0 inches (185.42 cm). In this variation of the preferred embodiment, the triple offset coil springs 30 have a dimension of length of 3.44 inches (8.74 cm). When the pattern includes twenty-four rows, the triple offset coil springs 30 are disposed within a total area of 36.5 inches (92.71 cm) by 78.0 inches (198.12 cm). In this variation of the preferred embodiment, the triple offset coil springs 30 have a dimension of length of 3.38 inches (8.59 cm). FIG. 3 shows a schematic plan view of a pat¬ tern of rows and columns in an innerspring assembly for a full mattress in which the triple offset coil springs of the present invention may be used. The pattern com¬ prises twenty-two or twenty-four rows and sixteen columns. When the pattern includes only twenty-two rows, the triple offset coil springs 30 are disposed OMΓI within a total area of 51.5 inches (130.81 cm) by 73.0 inches (185.42 cm). In this variation of the preferred embodiment, the triple offset coil springs 30 have a dimension of length of 3.44 inches (8.74 cm). When the pattern includes twenty-four rows, the triple offset coil springs are disposed within a total area of 51.5 (130.81 cm) inches by 78.0 inches (198.12 cm). In this variation of the preferred embodiment, the triple offset coil springs 30 have a dimension of length of 3.38 inches (8.59 cm). FIG. 4 shows a schematic plan view of a pat¬ tern of rows and columns in an innerspring assembly for a queen mattress in which the triple offset coil spring of the present invention may be used. The pat- tern comprises twenty-four rows and eighteen columns. The triple offset coil springs 30 are disposed within a total area of 58.5 inches (148.59 cm) by 78.0 inches (198.12 cm), and the triple offset coil springs 30 have a dimension of length of 3.38 inches (8.59 cm). FIG. 5 shows a schematic plan view of a pat¬ tern of rows and columns in an innerspring assembly for a king mattress in which the triple offset coil spring of the present invention may be used. The pattern comprises twenty-four rows and twenty-three columns 24. The triple offset coil springs are dis¬ posed within a total area of 74.5 inches (189.23 cm) by 78.0 inches (198.12 cm), and the triple offset coil springs 30 have a dimension of length of 3.38 inches (8.59 cm) . In FIGS. 2, 3, 4 and 5, innerspring assem¬ blies of the preferred embodiment are stress relieved at 450°F (232°C). The coil springs 30 used in these preferred embodiments have first offset segments one and one_half inches (3.81 cm) long and second offset segments one and one quarter inches (3.18 cm) long. χ gtj E OMP The width of the terminal convolutions is two and three quarter inches (6.99 cm). FIG. 6 shows a plan view of an improved ter¬ minal convolution 10. The terminal convolution 10 de- fines a first offset segment 12. In the preferred embodiment, the first offset segment 12 is about one and one half inches (3.81 cm) long. The terminal con¬ volution 10 further defines a second offset segment 14. In the preferred embodiment, the second offset seg- ment 14 is about one and one quarter inches (3.18 cm) long. The first offset segment 12 and the second offset segment 14 are disposed substantially in a plane and substantially parallel to one another. A third offset segment 16 defined by the terminal convolution 10 is disposed substantially in the plane and substantially at right angles to the first offset segment 12 and the second offset segment 14. A knot side 18 including a knot 19 is also defined by the terminal' convolution 10, disposed in the plane and substantially parallel to the third offset segment 16. A preferred width measured from the knot 19 to the third offset segment 16 is about two and three quarters inches long (6.99 cm). Qf course, the invention is not limited to a- triple offset spring having a terminal convolution of these exact dimensions. Rather, the invention is equal¬ ly directed to the ratios that produce the advantages described here. The triple offset coil spring of F.IG. 6 dif- fers from traditional coil springs in several respects. A most important difference, however, is that the arc side of the traditional terminal convolution 20 is shaped into a third offset segment 16 in the improved terminal convolution 10 of the triple offset coil spring. This shaping of the arc side of traditional • springs offers a surprisingly wide range of advantages. -^ E OMPI SUBSTITUTE SHEET V ^ 50 First, the third offset segment 16 permits greater engagement of border wire at innerspring unit assembly borders than is permitted by traditional springs with rounded arc sides. Hence, this feature contributes to firmness at borders of rows defined by a plurality of third offset segments 16. Second, the decreased width of the terminal convolutions of the triple offset coil provides for a greater clearance between columns of traditional inner- spring assemblies of a given coil density. This offers the advantage that squeaking and/or clicking occasioned by the proximity of adjacent coil springs may be mini¬ mized or eliminated at currently used coil densities. Alternatively, the decreased width of the terminal convolution of the triple offset coil affords an option of increasing coil density without increasing current risks of squeaking and/or clicking resulting from contact between adjacent coil springs. • • Another important difference from traditional coil springs lies in increased dimensions of length of the first offset segment 12 and the second offset seg¬ ment 14 of FIG. 6 relative to the width of the terminal convolution of the triple offset coil. These increased dimensions permit more turns of cross helical between adjacent triple offset coil springs comprising the im¬ proved terminal convolution ' s 10. In contrast, tradi¬ tional coil springs comprising traditional terminal convolutions permit fewer turns of helical wire between adjacent coil springs, such that there is much unsup- ported cross helical and also much of each terminal convolution remains unengaged by cross helical in the coil spring assembly. This lack optimum of cooperation between cross helical and adjacent terminal convolutions impedes the achievement of optimum mattress firmness. This difference offers the advantage of per¬ mitting better utilization of wire at critical loca- -^ J E UBSTITUTE SHEET OMPI tions within the innerspring unit. First, additional firmness is provided within the improved assembly be¬ tween adjacent rows of coil springs because there is less unsupported cross helical between the rows and an optimal amount of engagement of cross helical and ter¬ minal convolution wire such that the relative motion between adjacent coil springs in the assembly is well controlled. Further, at borders defined by the first or second offset segments of coil springs disposed in terminal rows of the innerspring unit assembly, longer offset segments permit greater engagement with border wire per unit of border length. This provides addi¬ tional firmness at borders of columns defined by a plurality of first offsets 12 or second offsets 14. FIG. 7 shows a side elevation view of a triple offset coil 30 of the present invention. In the presently preferred embodiment, the triple offset coil 30 has a dimension of height of about five and one- eighth inches (7.67 cm). The triple offset coil 30 comprises a plurality of convolutions 32 including a center convolution 35. The center convolution 35 has an inner diameter, in the presently preferred embodi¬ ment, of just over one and one half inches (3.81 cm). The coil is formed on a coiling machine. The terminal convolutions are considerably larger than the center convolutions. This coil is then transferred into a forming station where two dies are closed against opposing ends of the terminal convolution. The dies consist of straight segment pieces adapted to engage . the inside and outside diameters of the terminal con¬ volution. The segment engaging the outside diameter of the terminal convolution presses against the straight segment on the inside diameter. The wire of the op¬ posing ends of the terminal convolution is then trapped between the two die segments and the first and second offset segments are formed. That portion of the terminal -gtJRE_ξ f OMPI SUBSTITUTE SHEET fa convolution that is not restrained between the two dies will be reshaped so that it defines a lesser degree of curvature than before the coil was passed to the form¬ ing station. Thus, the process of restraining and press- ing opposing sides of the terminal convolution to form first and second offset segments also results in the contour forming the third offset segment. In the claims, this is the process of reshaping the arc sides to form triple offset segments. Of course, it should be understood that vari¬ ous changes and modifications to the preferred embodi¬ ments described above will be apparent to those skilled in the art. The foregoing description of the presently preferred embodiments has been provided merely to illus- trate several preferred forms of the invention. Rather, it is intended that the scope of this invention be de¬ fined by the following claims, including all equiva¬ lents.

Claims: CLAI S : 1. In an innerspring assembly having a plurality of coil springs arranged, at a selected coil density, in a pattern of rows and columns, said columns disposed transversely to said rows, each of said coil springs defining first and second terminal convolutions, each of said convolutions defining first and second offset segments disposed substantially in a plane and substan¬ tially parallel and opposite to one another, and each of said convolutions further defining an arc side and a knot side disposed substantially in said plane, and substantially parallel and opposite to one another, where adjacent first and second offset segments defined by terminal convolutions in adjacent rows are engaged by a cross helical, the improvement comprising: said coil springs comprising terminal con¬ volutions having a first offset segment, a second offset segment and a third offset segment said first offset segment being parallel to said second offset segment and said third offset segment being disposed between said first offset segment and said second offset segment, the ratio of the center segment con¬ necting the centers of said first offset segment and said second offset segment to the distance from said center segment to the third offset segment being suf¬ ficiently large such that said coil springs are separated to prevent squeaking and clicking and the firmness of the borders of said assembly is increased while the selected coil density is maintained. 2. The improvement of Claim 1, wherein said ratio is more than about 2.6. 3. The improvement of Claim 1, wherein said ratio is about 3.3. >fa 4. The improvement of Claim 1, wherein the triple offset coil springs have a dimension of width and a dimension of length, and wherein a ratio of the dimension of width to the dimension of length less than about 0.4. 5. The improvement of Claim 1, wherein the tri¬ ple offset coil springs have a dimension of width and a dimension of length, and wherein a ratio of the dimen¬ sion of width to the dimension of length at about 0.4. 6. The improvement of Claim 1, wherein the triple offset coil springs comprise a first offset seg¬ ment, a second offset segment disposed in a substant- ally parallel relationship to the first offset segment, and a third offset segment adjoining the first offset segment and the second offset segment at substantially perpendicular angles. 7. The improvement of Claim 1, wherein the tri¬ ple offset coil springs have a dimension of width and a first dimension of length, said triple offset springs comprising: first offset segments, having a second dimen¬ sion of length and disposed along at least a portion of the width of the triple offset coil springs; second offset segments, having a third dimen- sion of length and disposed substantially parallel to the first offset segments and third offset segments, having a fourth dimen¬ sion of contoured length and adjoining the first and second offset segments. 8. The improvement of Claim 7, wherein: OMPI the dimension of width is about 2.75 inches (6.99 cm); the first dimension of length is about 3.4 inches (8.64 cm); the second dimension of length is about 1.25 inches (3.18 cm); and the third dimension of length is about 1.5 _ inches (3.81 cm). 9. The improvement of Claim 1, wherein the plural- ity of coil springs are disposed in a pattern of 22 rows and 11 columns in an area of 73 inches (185.42 cm) by 36.5 inches (92.71 cm). 10. The improvement of Claim 9, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.44 inches (8.74 cm). ■ -SO¬ IL The improvement of Claim 1, wherein the plural¬ ity of coil springs are disposed in a pattern of 24 rows and 11 columns in an area of 78 inches (198.12 cm) by 36.5 inches (92.71 cm). 12. The improvement of Claim 10, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.38 inches (8.59 cm). . 13. The improvement of Claim 1, wherein the plural- • ity of coil springs are disposed in a pattern of 22 rows and 16 columns in an area of 73 inches (185.42 cm) by 51.5 inches (130.81 cm). 14. The improvement of Claim 13, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc -sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.44 inches (8.74 cm). 15. The improvement of Claim 1, wherein the plural- ity of coil springs are disposed in a pattern of 24 rows and 16 columns in an area of 78 inches (198.12 cm) by 51.5 inches (130.81 cm). 16. The improvement of Claim 15, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.38 inches (8.59 cm). 17. The improvement of Claim 1, wherein the plural- ity of coil springs are disposed in a pattern of 24 rows and 18 columns in an area of 78 inches (198.12 cm) by 58.5 inches (148.59 cm). OMPI SUBSTITUTE SHEET ^™ 18. The improvement of Claim 17, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.38 inches (8.59 cm). 19. The improvement of Claim 1, wherein the plural¬ ity of όbil springs are disposed in a pattern of 24 rows and 23 columns in an area of 78 inches (198.12 cm) by 74.5 inches (189.23 cm). 20. The improvement of Claim 19, wherein the triple offset coil springs include a plurality of non-terminal convolutions disposed centrally to the first and second terminal convolutions, where the terminal convolutions include third offset segments formed by reshaping the arc sides of said traditional coil springs so that they define a lesser degree of curvature than is defined by the non-terminal convolutions, and wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm); and the triple offset coil spring has a dimension of length of about 3.38 inches (8.59 cm). 21. An improved coil spring for an innerspring assembly including a plurality of coil springs disposed adjacent to each other in a pattern of rows and columns, said coil springs respectively defining terminal convolu¬ tions, each of said terminal convolutions defining first and second offset segments disposed substantially in a plane and substantially parallel and opposite to each other, said first and second offset segments spaced apart at a distance equal to a dimension of length of the coil springs, and each of said convolutions further defining a knot side and an arc side disposed substan¬ tially in said plane, substantially parallel and opposite to each other, and wherein the improvement comprises: a third offset segment, having a contoured dimension of length, and formed by reshaping the arc side opposite the knot side such that the third offset segment further defines a limited degree of curvature. 22. The improvement of Claim 21, wherein the first offset segment has a first dimension of length, the second offset segment has a second dimension of length and the triple offset coil spring has a third dimension of width, said first, second and third dimen- sions yielding a ratio of about 1.25 to 1.50 to 2.75 respectively. 23. The improvement of Claim 21, wherein the first offset segment has a dimension of length of about 1.25 inches and wherein the second offset segment has a dimension of length of about 1.50 inches (3.81 cm). IT TE HE 24. The improvement of Claim 21, wherein the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm). 25. The improvement of Claim 21, wherein: the first offset segment has a dimension of length of about 1.25 inches (3.18 cm); the second offset segment has a dimension of length of about 1.50 inches (3.81 cm); and the triple offset coil spring has a dimension of width of about 2.75 inches (6.99 cm).

Inventors: WAGNER ROBERT F, WAGNER, ROBERT, F.
Applicants: SEALY, SEALY, INCORPORATED
Application year: 1984
Main classification: A47C23
IPC codes: A47C27