Abstract:
A mattress spring structure ( 10 ) is provided with a strengthened central area (C) thereon to provide greater support for a user&#39;s body lumbar region when received thereon. The support is provided with a strengthening structure ( 30 ) having a continuous frame member ( 54 ) and a strengthening pattern ( 53 ). The continuous frame ( 54 ) encircles coil springs ( 12 ) over a major expanse of the mattress&#39;s central area (C); this frame is connected to mattress coils along the frames longitudinal ( 34, 36 ) and traverse ( 38, 40 ) segments. The strengthening pattern ( 53 ) has two metal bars ( 51, 52 ) arranged inside and connected to the continuous frame member ( 54 ). The strengthening pattern ( 53 ) may be connected to the spring coils ( 12 ) and contain additional metal straps ( 56, 59 ). The strengthening structure ( 30 ) is positioned and arranged to causes substantially uniform depression of adjacent coil springs to the continuous frame member ( 54 ) in the lumbar zone thereby eliminating any undesired upward pressure into the user&#39;s back.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of patent application Ser. No. 10/502,970, filed Mar. 2, 2005 now U.S. Pat. No. 6,996,866, title MATTRESS STRUCTURE WITH AN IMPROVED LUMBAR ZONE, which claims priority to International Application No. PCT/US02/02460, filed Jan. 29, 2002. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to mattress structures and in particular to a mattress spring structure with an improved lumbar zone support. 
     BACKGROUND OF THE INVENTION 
     In the past, mattress construction concentrated on the innerspring construction to support the user&#39;s lumbar region such as, for example, by varying spring tensions, and material gauge. U.S. Pat. No. 5,325,553 to Ripley et al. provided more attention to the mattress, specifically a spring structure providing support with a continuous frame that encircled coil springs over a major expanse of the central area of the mattress that usually receives and supports the lumbar region of the user&#39;s back. While the problem of lumbar support has been partially solved by the mattress structure of Ripley et al., there remains the particular problem of the mattress springs on either side of the traverse frame bars depressing lower than the said bars when the user is received thereon, whereby creating undesired upward pressure into the user&#39;s back. This has been a particular problem that prior art mattress structures have attempted to address. 
     In particular, the mattress structures disclosed by U.S. Pat. No. 2,383,157 to Pink and U.S. Pat. No. 2,131,071 to Radnus both amplify the firmness of certain surface areas of a mattress spring structure by using metallic strips/wire to frame two separate reinforced areas per mattress. 
     U.S. Pat. No. 3,242,505 to Tyhanic discloses a mattress structure that uses multiple flat bands that traverse the mattress covering the center of the spring coils. The flat bands are connected to an encircling wire frame thereby creating a more uniform horizontal depression of the mattress structure when the user is received on said mattress. 
     The mattress structures disclosed by U.S. Pat. No. 4,122,566 to Yates and U.S. Pat. No. 5,570,484 to Ogle create two bordered areas of coil springs per mattress spring structure surface, four total, thereby increasing firmness over specific areas of said mattress. 
     The mattress structure disclosed by U.S. Pat. No. 4,180,877 to Higgins increases mattress spring structure firmness in selected areas using a welded wire grid structure attached to the opposite sides of said mattress. 
     U.S. Pat. No. 4,348,014 to Litkewycz discloses a mattress structure that increases the firmness of a bedding unit through the use of an auxiliary panel that has a wire border and a plurality of torsion bar springs extending between opposites portions of the peripheral wire and are connect to said wire thereby creating cooperation between coil springs when depressed. 
     The mattress structure disclosed by U.S. Pat. No. 4,369,534 to Wright increases the firmness of a pre-selected center area of a mattress spring assembly using a grid structure attached to the opposite sides of the mattress. The grid structure is comprised of plastic straps extending diametrically across the mattress in the center third area and overlaid by a preformed wire grid. The plastic straps and wire grid are attached to pre-assembled spring core by conventional connectors such as metal clips and/or hog rings. 
     U.S. Pat. No. 5,027,459 to Perry, Jr. et al. discloses a mattress structure that creates surface lift through “trampoline” grids on each horizontal plane of the mattress that are connected to the mattress perimeter by a band apparatus. 
     While the above mentioned prior art mattress structures provide a degree of added support and firmness to certain surface areas of mattress spring structures, they do so with the inefficient use of materials and overly complicated designs. The costs of materials and manufacturing are not taken into account by the prior designs. The complicated structures make it difficult to construct and increase the time to manufacture, thus raising the manpower cost per mattress and lowering the volume of output. Not only do the excessive amounts of material add to the complicated manufacturing process, they also increase the material cost per mattress. 
     Therefore, what is need is a mattress structure with an improved lumbar zone that does not create an undesired upward pressure into the back of a user&#39;s when received thereon, and which can be economically provided. 
     SUMMARY OF THE INVENTION 
     The above noted problems are herein solved by the present invention in where provided is a mattress spring structure with a strengthened central area which provides greater support for a user&#39;s body lumbar region when received thereon. The mattress spring structure has a plurality of coil springs arrayed in longitudinal and traverse rows within framed borders. The total number, size, compression, and alignment of springs used may vary. 
     A strengthening structure having a continuous frame member and a strengthening pattern is mounted on the coil springs in such a manner to provide the added support. The continuous frame is a single rod shaped to have a rectangular planner profile encircling and defining the central area of the mattress surface. The continuous frame is connected to first and last traverse rows of coil springs in the central area and extra central area traverse coil rows next adjacent the said first and last rows. The frame also is connected to adjacently paired longitudinally arrayed coil springs in the central area at both lateral sides of the springs structure. 
     The strengthening pattern is located within the area encompassed by the continuous frame. The pattern has two metal bars with opposing ends which connect to the continuous frame. The pattern may also comprise a signal bar with opposing ends. The strengthening pattern may contain straps connecting the bars for added support. The strengthening pattern may be attached to the coil springs with clip fasteners in a manner similar to the frame member. The connection may also be made with hog rings, windings, and fasteners commonly used in this art. Additionally, the strengthening pattern may lie freely on the coil springs. 
     The strengthening pattern may be provided in a number of advantageous and economical configurations. In a first configuration according to the present invention, the strengthening pattern&#39;s support bars cross one another substantially in the central region of the area encompassed by the frame. In this configuration, a first support bar extends from the upper left region of the frame member to the lower right region of the frame member. A second support bar extends from the upper right region of the frame member to the lower left region of the frame member. 
     It is to be appreciate that metal straps may be included in the above mentioned strengthening pattern configuration, such that a first strap connects the upper parts of the support bars in the upper region of the area encompassed by the continuous frame. A second strap connects the lower parts of the support bars in the lower region of the area encompassed by the continuous frame. A third strap connects the upper right part of one support bar to the lower right part of the other support bar in the right side of the area encompassed by the continuous frame member. Finally, a fourth strap connects the upper left part of one support bar to the lower left part of the other support bar in the left side of the area encompassed by the continuous frame member. 
     In another configuration, the strengthening pattern&#39;s support bars may be provided substantially parallel such that the support bars traverse the mattress area encompassed by the continuous frame member. In still another configuration, the strength pattern is a single bar with opposing ends shaped to have a rectangular planer profile. 
     In accordance with these and other objects of the present invention, there is provided a mattress spring structure having a plurality of coil springs arrayed in longitudinal and traverse rows of such coil springs. These coil springs extend between upper and lower margins and opposite side margins of the spring structure with the coils in each row aligned with the others. In each row the structure including a border piece which defines the upper, lower and side margins. Fastening devices secure each coil spring of each traverse row to a coil spring of an adjacent traverse row. A central area of the spring structure being defined by a selected succession of traverse rows of coil springs; and a strengthening structure receivable exteriorly against a major expanse of the spring structure central area. The strengthening structure has a continuous frame member encircling a major expanse of the spring structure&#39;s central area. 
     The strengthening structure includes a first traverse frame segment extending along a juncture of the coil springs of a traverse row first in selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together the first traverse segment and each joined pair of coil springs in the first succession traverse row and the extra succession traverse row adjacent thereto. The strengthening structure further includes a second traverse frame segment extending along a juncture of the coil springs of a traverse row last in the selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together the second traverse segment and each joined pair of coil springs in the last traverse row and the extra succession traverse row adjacent thereto. Further included is a pair of longitudinal frame segments spaced inwardly from the spring structure side margins and extending longitudinally in between adjacent longitudinal rows of coil springs, opposite ends of the traverse frame members being connected to opposite ends of the longitudinal frame members. Joining members, which closely join together the longitudinal frame segments and successive ones of pairs of coil springs, comprised each of a coil spring in one of the adjacent longitudinal rows and a coil spring in the other of the adjacent longitudinal rows. A strengthening pattern, located within and connected to the continuous frame member, the pattern is receivable exteriorly against the spring structure encircled by the continuous frame member, adapted to provide additional support to the user&#39;s lower back and causing uniform depression of coil springs limiting undesired upward pressure. 
     According to a still further feature of the present invention, there is provided a mattress spring structure having a plurality of coil springs arrayed in longitudinal and traverse rows of the coil springs between upper and lower margins and opposite side margins of the spring structure. These coils in each row aligned with the others in each row. The structure including a border piece which defines the upper, lower and side margins. Fastening devices secure each coil spring of each traverse row to a coil spring of an adjacent traverse row. A central area of the spring structure is defined by a selected succession of traverse rows of coil springs. Further provided is a strengthening structure received exteriorly against a major expanse of the spring structure central area. The strengthening structure has a continuous frame member encircling the major expanse of the spring structure central area. The strengthening structure includes a first traverse frame segment extending along a juncture of the coil springs of a traverse row first in selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together said first traverse segment and each joined pair of coil springs in the first succession traverse row and the extra succession traverse row adjacent thereto. A second traverse frame segment extending along a juncture of the coil springs of a traverse row last in the selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together the second traverse segment and each joined pair of coil springs in the last traverse row and the extra succession traverse row adjacent thereto. A pair of longitudinal frame segments spaced inwardly from the spring structure side margins and extending longitudinally in between adjacent longitudinal rows of coil springs, opposite ends of the traverse frame members being connected to opposite ends of the longitudinal frame members. Joining members, closely joining together the longitudinal frame segments and successive ones of pairs of coil springs, comprise each of a coil spring in one of the adjacent longitudinal rows and a coil spring in the other of the adjacent longitudinal rows. A pair of elongated metal elements possessing opposing ends, located within and connected to the continuous frame member, the elongated metal elements are receivable exteriorly against the mattress spring structure encircled by the continuous frame member wherein one of the elongated metal elements traverses the other elongated metal element. 
     According to still another further feature of the present invention, provided is a mattress spring structure having a plurality of coil springs arrayed in longitudinal and traverse rows of such coil springs between upper and lower margins and opposite side margins of the spring structure. These coils in each row aligned with the others in each row. The structure including a border piece which defines the upper, lower and side margins. Fastening devices secure each coil spring of each traverse row to a coil spring of an adjacent traverse row, a central area of the spring structure being defined by a selected succession of traverse rows of coil springs. A strengthening structure is received exteriorly against a major expanse of the spring structure central area. The strengthening structure has a continuous frame member encircling the major expanse of the spring structure central area, and includes a first traverse frame segment extending along a juncture of the coil springs of a traverse row first in selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together the first traverse segment and each joined pair of coil springs in the first succession traverse row and the extra succession traverse row adjacent thereto. A second traverse frame segment extending along a juncture of the coil springs of a traverse row last in the selected succession of such with an extra succession traverse row adjacent thereto. Joining members closely join together the second traverse segment and each joined pair of coil springs in the last traverse row and the extra succession traverse row adjacent thereto. A pair of longitudinal frame segments spaced inwardly from the spring structure side margins and extending longitudinally in between adjacent longitudinal rows of coil springs, opposite ends of the traverse frame members being connected to opposite ends of the longitudinal frame members. Joining members, closely joining together the longitudinal frame segments and successive ones of pairs of coil springs, comprise each of a coil spring in one of the adjacent longitudinal rows and a coil spring in the other of the adjacent longitudinal rows. A pair of elongated metal elements possessing opposing ends, located within and connected to the continuous frame member, the elongated metal elements are receivable exteriorly against the spring structure encircled by the continuous frame member wherein the pair of metal elements are substantially parallel. 
     The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the accompanying drawings, where like structure is indicated with like reference numerals and in which: 
         FIG. 1  is a plan view of a mattress spring structure constructed in accordance with the present invention; 
         FIG. 2  is a plan view of a strengthening structure of a mattress structure comprising a continuous frame member and strengthening pattern with support bars crossing substantially in the center of the frame&#39;s encompassed area according to the present invention; 
         FIG. 3  is a section view, on enlarged scale, through the frame member taken on the section line  3 — 3  in  FIG. 2 ; 
         FIGS. 4   a  and  4   b  are illustrations showing methods of connecting a support bar to a frame member of a strengthening structure according to the present invention; 
         FIG. 5   a  is a plan view of a strengthening structure with a substantially parallel arrangement of support bars of a strengthening pattern connected to longitudinal boarders of a frame member according to the present invention; 
         FIG. 5   b  is a plan view of a strengthening structure with support bars of a strengthening pattern in a substantially rectangular configuration positioned within a continuous frame member according to the present invention; 
         FIG. 5   c  is a plan view of a strengthening structure with support bars of a strengthening pattern in a substantially parallel configuration positioned within a continuous frame member and having cross members according to the present invention; 
         FIG. 6  is a fragmented plan view of the strengthening pattern as shown in  FIG. 2  with metal straps included in the strengthening pattern according to the present invention; 
         FIG. 7  is a fragmented plan view of a mattress structure with a support bar of a strengthening pattern with nearly right-angle bends to prevent the bar from substantially passing through a surface area of individual coil springs according to the present invention; 
         FIG. 8  is a fragmented plan view of a mattress structure with a straight support bar of a strengthening pattern diagonally crossing the mattress passing through the upper surface area of individual the coil springs according to the present invention; 
         FIG. 9  is a fragmented plan view of a mattress structure with a straight support bar of a strengthening pattern traversing the mattress without substantially passing through an upper surface area of individual coil springs according to the present invention; 
         FIG. 10  is a fragmented plan view of a mattress structure with a straight support bar of a strengthening pattern passing through an upper surface area of individual coil springs while traversing the mattress according to the present invention; 
         FIG. 11  is an exploded perspective view of the strengthening structure shown in  FIG. 1  according to the present invention; and 
         FIG. 12  is a fragmentary vertical sectional view depicting a manner of securing a strengthening structure according to the present invention to coil springs with prior art clip fasteners. 
     
    
    
     It is noted that the drawings of the invention are not to scale. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a mattress spring structure  10  comprises a plurality of coil springs  12  which can be arrayed in longitudinal and traverse rows. As shown, these rows extend crosswise of the structure between left and right side margins of the frame as defined by the respective longitudinal or side margin parts  14 ,  16  of a conventional frame border piece  18 . The rows also extend longitudinally between top and bottom frame margins  20 ,  22  defined by traverse margin parts of a border piece  18 . The coil springs  12  depicted in the  FIG. 1  embodiment are all the same diameter and arrayed such that each coil spring in a given traverse or longitudinal row is aligned with the others in the given row. 
     The total number of springs used may vary as can spring size, compression, and the like. In addition, the coil spring alignment may vary such as, for example, a coil spring in one row need not align with one in an adjacent row. However, in a preferred embodiment, the springs in the uppermost and lowermost traverse rows of springs included in a spring structure central area C should be at least in part pairable with the extra central area rows of springs adjacent each upper and lowermost rows. Provided the coils in such a manner ensures that the coil springs in these traverse rows can be companion connected to each other and to a strengthening structure  30  as depicted in  FIG. 1  which is described in greater detail in a later section. In like manner, springs in the longitudinal rows at the side parts of the central area should at least, in part, be pairable with adjacent row springs. 
     Each traverse row of coil springs of the mattress spring structure  10  is joined to an adjacent row in known manner, for example, with helical wire windings  26 , these windings also being secured to a border piece  28 . Further, the perimeter coil springs each can be connected to the border piece with known types of connectors (not shown). 
     As seen from  FIG. 2 , the strengthening structure  30  comprises two major components a frame member  54  and a strengthening pattern  53 . Frame member  54  is a unitary component having longitudinal side segments  34 ,  36  joined to traverse segments  38 ,  40  in continuous encircling course. The frame member  54  conveniently can be fabricated from a length of high carbon steel rod of, e.g., 6 or 9 gauge which is shaped into the rectangular plan profile shown, and the confronting rod opposite ends welded together as at  39 . The cross-section of the frame member  54  shown by the section view of  FIG. 3 , taken on the line  3 — 3  in  FIG. 2 , is rectangular but it is understood that the same could be square, hexagonal, circular, etc, as well. 
     The strengthening pattern  53  comprises two metal support bars received exteriorly over the area of the mattress spring structure  10  encircled by the frame member  54 . The support bars  51 , 52  preferably are a polyethylene coated  14  gauge wire, however, other gauges and bar-types may be suitably used for the purpose described herein. The support bars  51 ,  52  have opposing ends which connect to the frame member  54  at corners  61 , such as by a weld or any other mounting means. For example,  FIG. 4   a  shows the strengthening pattern  53  connected to the frame by ring  60  connections, and  FIG. 4   b  illustrates a conventional wire wrap connection. Further, the strengthening pattern  53  may be connected to the frame member  54  by hog rings, windings, or combinations thereof. Additionally, if desired, the strengthening pattern  53  may be positioned floating between the frame member  54 . 
       FIG. 2  depicts bar  52  extending from the upper left corner of the frame member  54  to the lower right corner of the frame member crossing over the upper surface of support bar  51  which is extending from the upper right corner of the frame member to the lower left corner of the frame member. Further, it is understood that the strengthening pattern  53  could have support bar  51  traversing over the upper surface of support bar  52 . 
       FIG. 5   a  depicts another embodiment of strengthening pattern  53  with support bar  51  and support bar  52  substantially parallel traversing the area encircle by the frame member  30 . Support bar  51  is located above bar  52  in the framed area. One end of support bar  51  is joined to longitudinal frame segment  34 , the opposing end of the said bar is connect to longitudinal frame segment  36  in the manner described above. Support bar  52  is connected to the longitudinal frame segments  34 ,  36  in the same manner. It is further understood that the support bars  51 ,  52  can connect anywhere on the longitudinal frame segments  34 ,  36 . 
       FIG. 5   b  depicts still another embodiment of the strength pattern  53  with support bar  85 . Support bar  85  is a unitary component having longitudinal segments  91 ,  93  joined to traverse segments  90 ,  92  in a continuous encircling course. The support bar  85  is a rod shaped in the rectangular plan profile illustrated by  FIG. 3 , and the confronting rod opposite ends held together by weld  80 . For added support, cross members  71   a–d  (indicated by dashed lines) may be used to connect together opposed segments of both frame member  30  and strength pattern  53 . The cross members  71   a – 71   d  may be welded at ends between opposed segments and/or each wrap therebetween, such that any compressive forces realized by any frame segment of frame member  30  will be distributed to its respective member of the strength pattern  53 , and vice-versa. The strength pattern  53  may be secured to the mattress coil springs in a similar fashion as the frame member  30  as will be explained in a later section. 
       FIG. 5   c  depicts yet another embodiment of the strength pattern  53  with a plurality of support bars  51 ,  52  provided substantially parallel to traverse portions  38 ,  40  defining the width of the frame member  54 . The support bars  51 , 53  are rod shaped in the rectangular plan profile illustrated by  FIG. 3 , and are held by a plurality of cross members  71  for added support. The cross members  71  may be wired wrapped at ends around the exterior support bars  51   a ,  51   b  and threaded through the remaining support bars  52   a–c  to maintain the shape of the strength pattern  53 . 
       FIG. 6  is a fragmented view of the strengthening pattern  53  similar to the pattern depicted in  FIG. 2  to include metal straps  56 ,  57 ,  58 ,  59  having opposing ends. Strap  56  traverses mattress surface in the upper region of the area encircled by frame member  54  joining the upper part of support bar  51  to the upper part of support bar  52 . The opposing ends of strap  56  are welded to support bars  51 ,  52  at welds  62  A, B respectively. Strap  58  traverses mattress surface in the lower region of the area encircled by frame member  54  joining the lower part of support bar  51  to the lower part of support bar  52 . 
     The opposing ends of strap  58  are welded to support bar  51 ,  52  at welds  62  E, F respectively. Strap  57  extends longitudinally over the mattress surface in the left region of the area encircled by frame member  54  joining the upper part of support bar  52  to the lower part of support bar  51 . The opposing ends of strap  57  are welded to support bar  52 ,  51  at welds  62  C, B respectively. Strap  59  extends longitudinally over the mattress surface in the right region of the area encircled by frame member  54  joining the upper part of support bar  51  to the lower part of support bar  52 . The opposing ends of strap  59  are welded to support bar  51 ,  52  at welds  62 H, G respectively. 
       FIG. 7  is a fragmented view of support bar  51  diagonally crossing the mattress spring structure  10  with a plurality of substantially right angles positioned to avoid substantially passing through the upper plan surface area of the individual coil springs  12 . It is understood support bar  52  would cross the mattress spring structure  10  in a similar manner respective to support bar  51 . 
       FIG. 8  is a fragmented view of support bar  51  diagonally crossing the mattress spring structure  10 . The straight support bar  51  is positioned to substantially cross over the center area of the upper plan surface of the individual coil springs  12 . It is understood support bar  52  would cross the mattress spring structure  10  in a similar manner respective to support bar  51 . 
       FIG. 9  is a fragmented view of support bar  51  traversing the mattress spring structure  10 . The straight support bar  51  is positioned to substantially avoid passing through the upper plan surface area of the individual coil springs  12 . It is understood support bar  52  would cross the mattress spring structure  10  in a similar manner respective to support bar  51 . 
       FIG. 10  is a fragmented view of support bar  51  traversing the mattress spring structure  10 . The straight support bar  51  is positioned to substantially pass through the center plan area of individual coil springs  12 . It is understood support bar  52  would cross the mattress spring structure  10  in a similar manner respective to support bar  51 . 
     Placement positioning of the strengthening structure  30  as well as means by which it is secured to the frame structure is readily seen with reference to the exploded showing of  FIG. 11 . 
     With reference again to  FIG. 1 , strengthening structure  30  is mounted on the coil springs  12  in such manner as to encompass a major expanse of a selected succession of traverse rows of coil springs R 1 –R 7  which define the central area C of the mattress structure. In that disposition, the segments  38 ,  40  of the frame member  54  overlay the junctures, respectively, of the succession uppermost and lowermost coil spring rows R 1  and R 7  with respective frame upper area U and lower area L coil spring rows next adjacent to rows R 1  and R 7 . 
     The opposite ends of the segments  38 ,  40  it will be noted are spaced inwardly at least one spring diameter from the side margins parts  14 ,  16  of the mattress spring structure  10 . Such opposite ends are situated at a location intervening the lateral most longitudinal spring rows in the central area C and the next inboard or adjacent rows to the lateral most rows. The lateral most longitudinal spring row is indicated by  33 A and  33 B for the spring rows running adjacent segments  34  and  36 , respectively. 
     Segment  38  is connected to each of the traverse paired coil springs in row R 1  and the above adjacent central area traverse row, except no connection is provided to the springs provided adjacently in the lateral most rows  33 A and  33 B. In the illustrated embodiment, the connection is effected with conventional clip fasteners  50 , which are shown in  FIG. 12 . In other embodiments, the joining of the elements may be made with windings encircling the elements and the windings being deformed closely against the encircled structures. The connection may also be made with hog rings or other fasteners commonly used in this art. Segment  40  is connected in like fashion with the traverse row R 7  and the traverse row of area L next below. 
     The longitudinal frame segments  34 ,  36  are connected to paired coil springs of the longitudinal spring rows first and second closest to the side margins part  14 ,  16  of the mattress spring structure  10 . If the frame member  54  was made narrower, the frame segments  34 ,  36  could locate in between the second and third longitudinal spring rows in which case the segments would be connected to paired coils in these rows. The joining of the elements is in a manner similar to segments  38 ,  40  using clip fasteners  50  as seen in  FIG. 12 . The connection also can be made with hog rings or other fasteners commonly used in this art. 
     In  FIG. 11 , the strengthening pattern  53  is attached to the coil springs with clip fasteners  63  in a manner similar to the frame member  54 . The number and positioning of the clip fasteners  63  will vary according to the arrangement of the strengthening pattern  53 , number and size of coil springs  12 , and the like. The connection also can be made with hog rings, windings, fasteners commonly used in this art. It is also understood that the strengthening pattern  53  can lie freely on the coil springs  12 . 
     The sum effect of connecting the strengthening structure to the coil springs in the manner aforesaid is to restrict travel movement of these springs responsive to imposition of user body weight thereon. This strengthens the central zone C where the user&#39;s body lumbar region normally will be received. 
     The numbers of traverse rows of coil springs can be varied depending on spring size. The  FIG. 1  depiction is representative of a desired arrangement wherein the areas U and L have each the same number of rows ( 9 ) but at least two greater than used in the area C ( 7 ). 
     Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.