MXPA99002327A - Method and apparatus for forming pocketed springs - Google Patents

Abstract

Method and apparatus for forming strings (170) of springs (16) enclosed within pockets having flat overlapping side seams (172), thereby avoiding problems with false loft in mattress construction. Fabric is first formed into an envelope (33) having overlapping portions (A, B). The overlapping portions are then diverted away from one another to form an opening in the envelope, and springs which are compressed by a compressor (80) are inserted into the envelope through the opening. Following insertion of the springs, the overlapping portions are sealed together, individual pockets are created in the envelope, and the springs are rotated within their respective pockets to form a completed string of springs.

Description

METHOD AND APPARATUS FOR FORMING SEALED SPRINGS BACKGROUND OF THE INVENTION Field of the Invention The present invention is concerned with spring assemblies for mattresses, cushions and the like and more particularly, with new and improved methods and apparatus for forming series of enclosed springs. in cavities or chambers that have superimposed, flat side seams or seams that do not exhibit the disadvantageous condition found in the assemblies of the prior art known as "false fluff." Description of the Related Art Numerous techniques have been developed to build mattresses, cushions and the like. One such technique that has gained wide acceptance is known as Marshall's construction. In this construction an internal spring assembly comprises the core or center of the mattress or cushion and is fabricated from a plurality of springs, each individually encapsulated in a suitable fabric chamber or cavity. The cavities or spring chambers are preferably joined together in a series of predetermined length and are arranged in a tightly packed arrangement all with their longitudinal axes parallel to each other and with their ends defining a plane. In a construction REF. 29740 mattress, this arrangement of enclosed springs is usually covered with a padded foam and cloth pad to provide through this a sleeping surface. The series of coiled coil springs have been manufactured in different ways. In a first manufacturing method, an appropriate fabric was folded to the longitudinal half and sewn transversely at regular intervals to define cavities or chambers in which the springs were inserted. This method has been extensively replaced in the most recent times by a method that uses heat sensitive cloth and ultrasonic welding techniques instead of sewing. An example of series of coiled coil springs manufactured by the latter method is described in U.S. Patent No. 4,234,983, issued to Stumpf and assigned to the assignee herein. As described in U.S. Patent No. 4,234,983, a series of enclosed coil springs are formed by ultrasonically welding the coil springs into discrete chambers or cavities by first folding a heat-sensitive fabric to the longitudinal half and applying welds transversely to the longitudinal axis of the coil. the fabric Once the coil springs are inserted into the cavities or chambers, the cavities or chambers are closed by welding along a joint or seam running longitudinally to the series of coil springs, adjacent one end of the springs.

An apparatus for manufacturing the above spring series is described, for example, in U.S. Patent No. 4,439,977, also issued to Stumpf and assigned to the assignee herein. A disadvantage of the series of coil springs of the above construction is that the seam or joint running longitudinally to the series of coil springs creates two flaps of excess fabric material at one end of the enclosed springs. Some excess material is necessary along the seam or joint to provide the proper alignment of the series of springs in the fabrication and to ensure proper strength of the associated welds. However, when the series of coil springs are arranged to define an inner spring mattress or core or core cushion, the excess material projecting outward from the springs creates a false firmness which is known in the art as "false." Fluffy, "under the pad on the outer surface of the mattress or cushion. This condition of false fluffiness can cause undesirable and objectionable body depressions to form when a user lies on a mattress or cushion. Attempts have been made to eliminate false fluff by constructing a series of helical springs having a flat overlapping side seam or joint instead of an upper seam. A machine for the construction of such a series of coil springs is described, for example, in US Pat. No. 4, 986,518, also issued to Stumpf and assigned to the assignee hereof. However, such a machine has a complicated lifting mechanism for the insertion of springs that has proven to be unreliable under the conditions of manufacture. U.S. Patent 5,613,287 discloses a novel method and apparatus for forming series of enclosed springs having flat overlapping side seams or seams that eliminate false fluffing. In the St. Clair system, a heat-sensitive fabric belt passes over a diamond-shaped folding plate and a first fold is created in the fabric defining a first flap. Then, the fabric passes over a series of rollers, after which a hook element causes one edge of the fabric to be inversely rotated on the tape and forms a second fold. The second fold creates a second flap which is superimposed on the first flap. Next, the resulting fabric tube advances to a baffle station in which an arm member flexes the overlapping flap to form an opening in the tube. Then, a spring inserter inserts a spring transversely to the open tube. Next, the tube advances to a second baffle station in which the second flap is bent at its original overlapped relationship with the first flap to thereby close the tube with the spring inserted therein. Then, a weld is formed between the overlapping flaps. Then, transverse welds are formed in the tube between the adjacent helical springs to thereby define individual fabric chambers containing the springs. A first form of the apparatus for forming series of enclosed coil springs is described in U.S. Patent No. 2,093,531 issued to Werner. The apparatus disclosed therein comprises an insertion mechanism of the coil springs wherein an operator manually compresses a coil spring when using a lever. Then, a pre-formed cloth tube having stitched chambers formed therein is brought to the apparatus, after which the chambers are opened manually and the flaps of the tube are separated and placed on two spaced-apart tabs. The compressed spring is inserted into the chamber by depressing a foot pedal and sliding the spring between the tabs, after which the cloth tube can be extracted from the tabs and the flaps can be manually realigned to a closed condition. A disadvantage of the Werner apparatus is that it requires manual operation and is not adaptable to a high-speed assembly process. Clearly, the cloth tube must be pre-formed to define cameras. The cameras must be manually opened to insert the coil springs when using Werner tabs. There is no description, teaching or suggestion in Werner's patent of how a series of enclosed coil springs could be formed by using a fully automated process starting with an unfolded cloth tape and ending with a completely formed series of enclosed coil springs that have seams or flat overlapping side seams, as carried out by the Clair process mentioned above. While the St. Clair process and apparatus are remarkably advantageous with respect to the prior art for use in the production of high speed encircled coil springs, it is desirable to provide improvements in such a process and apparatus. In particular, it is desirable to reduce the number of steps in the process of automatically folding a fabric ribbon into a tube, inserting the coil springs into the fabric tube, forming flat overlapping seams or side seams in the fabric and forming individual chambers around the fabric. the springs. Thus, it has been found desirable to provide cushion or cushion constructions in which the inner spring assembly is enclosed within chambers having flat overlapping side seams or seams. In particular, it has been found desirable to provide such cushion or cushion constructions that do not exhibit a "false fluff" by virtue of excess material for chamber formation adjacent to the ends of the coil springs. In addition, it has been found desirable to provide coil springs series assemblies for internal spring constructions employing less cloth material for chamber formation than was required in previously known constructions. Still further, it has been found desirable to provide an apparatus for the construction of series of enclosed helical springs which are housed in the cavities or chambers having flat overlapping side seams or seams. It has been found that such an apparatus is effective, efficient and reliable in use and its structure can be easily upgradable with existing prior art equipment at an economic cost.

BRIEF DESCRIPTION OF THE INVENTION The present invention is an improvement over the invention described in commonly owned U.S. Patent No. 5,613,287, by providing a method and apparatus for forming series of enclosed coil springs, wherein a fabric belt is folded to define a tube having a first flap and a second flap glued below the first flap. Then, the flaps are separated in an insertion station of the coil spring without the need for one of the flaps to be flexed from the other flap to form an opening in the tube. After insertion of the coil spring, the second flap can be flexed to overlap the first flap or the opening can simply be closed with the second flap underlying the first flap. After this, the flaps can be welded together to form a flat overlapping side seam or join. Thus, the first deflection station of the flap as described in U.S. Patent No. 5,613,287 by St. Clair is eliminated. The folding of the tube in the present invention is carried out at the fabric feeding station, as used in the apparatus described in the St. Clair application.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other new features of the invention will become apparent upon reading the following detailed description taken in conjunction with the accompanying drawings, wherein: Figure 1 is a perspective view of a mattress of the art. previously partially cut to show a conventional internal spring construction; Figure 2 is a fragmentary side view of the internal spring of the prior art shown in Figure 1; Figure 3 is a partial perspective view of a feeding station of the fabric of an apparatus according to the present invention; Figure 4 is another partial perspective view of the feeding station of Figure 3 showing the fabric being folded thereon according to the invention; Figure 5 is a schematic end view of a cloth tube constructed in accordance with the present invention; Figure 6 is a schematic view of a spring insertion station according to the present invention illustrating a step in the process of the invention wherein a spring, in an uncompressed state, is positioned prior to its insertion into a tube of cloth; Figure 7 is a schematic view of the insertion station of the spring of Figure 6 showing the spring in a fully compressed state for insertion into a fabric flap; Figure 8 is a further schematic view of the insertion station of the spring of Figure 6 with the apparatus aligned for the insertion of the spring fully compressed to the fabric tube; Figure 9 is a schematic view of the insertion station of the spring of Figure 7 showing the spring inserted into the cloth tube; Fig. 10 is a schematic view of a deflector station of an apparatus according to a first form of the present invention illustrating a step in the process wherein the flaps of the cloth tube are realigned after the insertion of the spring; Figure 11 is a schematic view illustrating the apparatus for carrying out the next processing step according to the present invention wherein the flaps on the cloth tube are positioned for processing after the insertion of a spring therein; Figure 12 is a schematic view of a first soldering station of an apparatus according to the present invention, illustrating a step in the process of the invention wherein the flaps on the cloth tube are sealed in an overlapping manner; Figure 13 is a schematic view of a second welding station of an apparatus according to the present invention illustrating a step in the process of the invention where discrete cloth pockets or pockets are formed with coil springs encapsulated therein; Fig. 14 is a schematic view of a driving station of an apparatus according to the present invention illustrating a mechanism for stretching the cloth tube through the apparatus for processing; Fig. 15 is a schematic view of a final forming station of an apparatus according to the present invention illustrating a mechanism for properly orienting the spring within a cloth chamber or cavity; and Figure 16 is a schematic view illustrating an apparatus for carrying out a processing step according to a second form of the present invention wherein the flaps of the cloth tube are not reoriented as in Figures 10-15; Figure 17 is a schematic view of a first welding station of an apparatus according to the second form of the present invention wherein the flaps on the cloth tube are sealed; Fig. 18 is a schematic view of a second welding station of an apparatus according to the second form of the present invention, illustrating a step in the process of the invention where discrete cavities or cloth chambers are formed with coil springs encapsulated therein; Figure 19 is a schematic view of a drive station of an apparatus according to the second form of the invention, illustrating a mechanism for stretching the cloth tube through the apparatus for processing; Figure 20 is a schematic view of a final forming station of an apparatus according to the second form of the present invention illustrating a mechanism for properly orienting the spring in the cloth chamber; and Figure 21 is a fragmentary side view of a series of enclosed coil springs constructed in accordance with the principles of the present invention.

DETAILED DESCRIPTION Referring now to the drawings and initially to Figure 1, a mattress assembly of a type well known in the art, is designated in general by the reference numeral 10 and includes an internal core or core assembly 12. of the so-called construction of Marshall. The core 12 includes a series 14 of coil springs 16 within a cloth chamber 18, arranged in a tightly packed arrangement having a generally rectangular planar shape. For the purposes of the present description, the term "coil springs" can be used interchangeably with springs or coil springs. The coil springs 16 are all oriented with their longitudinal axes parallel to each other and to their ends-all falling in a common plane. A suitable cover 19 is provided for the inner spring core 12 and is commonly made of a quilted foam and / or fabric material that defines a sleeping surface. Referring now to Figure 2, a portion of the prior art series 14 of coil springs 16 enclosed in fabric chambers 18 is illustrated in side view and comprises a fabric belt 20 which is essentially folded in half lengthwise. The fabric is preferably sensitive to heat and is formed in a series of chambers spaced by transverse welds 22. The welds 22 define tapes 24 which connect the cavities or chambers to form a series 14 which may be of any pre-selected length. Because the fabric 20 is folded in half, a seam 26 is welded through the upper edge of the series 14, as seen in Figure 2 in order to close the chamber. This forms a pair of flaps 28, only one of which can be seen, which runs longitudinally to the series 14 above the plane defined by the upper ends of the coil springs 16. The flaps 28 are necessary to space or separate the welds of the joint 26 inwardly of the edges of the fabric 20 and thereby ensure an adequate strength of the joint 26, also as to provide an appropriate alignment of the series 14 in the manufacture. Turning now to FIGS. 3 and 4, a portion of an apparatus for constructing series of coil springs 16 enclosed in accordance with the present invention is designated generally by reference numeral 30. As later described herein, the apparatus will be discussed in terms of its progressive operating sequences, in the so-called address of the apparatus, which begins with the portion 30 consisting of a feeding station of the material of the chamber. In the feeding station 30, a heat-sensitive fabric belt 32 is fed to the apparatus through a diamond-shaped folding plate 34. Preferably, the fabric 32 is of a non-woven polypropylene composition, for example of a type sold under the trade name DUON. A guide bar 35 extends above the fabric 32 in spaced relationship to the folder plate 34 to ensure that the fabric 32 will lie flat on the plate 34. Adjustable guide bars 36 are positioned along the opposite edges of the fabric. fabric ribbon 32 for properly aligning the fabric 32 for folding. The fabric 32 travels over the edges 38 of the folding plate 34 which converge to a point 40. A pair of parallel spaced guide bars 44 extend below the plate 34 and extend from a frame member 42. The guide bars 44 are aligned with the point 40 of the folding plate 34 and may have a mounting structure that includes spring tensioning means (not shown) to urge them into a closely spaced relationship. The fabric 32 passes between the guide bars 44 and a first fold 46 in the fabric 32 is created, which defines a first flap which will be consistently designated later on the flap A. The fabric tape 32 passes immediately around a roll inactive 48 which extends from and is urged to rotate on the frame 42. As best seen in Figure 4, the fabric 32 then passes around a second roller 50. This roller 50 is articulated on a frame member (not shown), which is disposed opposite and spaced or detached from the frame 42. The roller 50 extends only for a portion of the width of the folded fabric 32 to create a loose edge 52 of fabric 32 passing around the free end 54 of the second. roll 50. A uniformly rounded hook member 56 extends from the frame 42 in proximity to the end 54 of the roller 50 and engages the loose edge 52 of the fabric 32 to cause the edge 52 to rotate inversely on the tape 32 and forming a second fold 58. The second fold 58 creates a second flap which will be consistently designated later herein as flap B. In accordance with the invention, the hook element 56 engages with the edge 52 of the fabric 32 such that the flap B is rolled up under the flap A. The tape 32, which has now been folded twice, then passes over a third roller 60 which is articulated for rotation in the frame 42 and the ribbon 32 leaves the fabric feeding station 30 in an essentially horizontal orientation. The configuration of the fabric 32 according to the invention after it leaves the feeding station 30 is shown schematically in Figure 5. The fabric 32 is formed in a tube 33 of fabric, preferably having an essentially flat tubular shape. with the flap A folded over a back portion 62 in the first fold 46 and the flap B folded over the back portion 62 in the second fold 58. In a preferred form, the flap A is approximately 15.2 cm (six inches) wide while flap B is about 7.6 cm (three inches) wide. Also, flap A overlaps preferably flap B by approximately 1.3 cm (one-half inch). It can be seen that the width of the flap A can be predetermined by the adjustable lateral alignment of the cloth tape 32 with respect to the point 40 of the folding plate 34. In addition, the width of the flap B can be predetermined by the proper positioning of the second roller 50 and the associated hook element 56. The fabric tube 33 thus constructed advances to a spring insertion station shown in Figure 6 and designated generally by the reference numeral 70. An insertion assembly of the coil spring is designated 72 and includes an upper plate 74 and a lower plate 76 arranged parallel to each other and spaced apart each other by approximately 0.95 cm (three eighths of an inch). The upper plate 74 has a circular opening 78 which is dimensioned to allow a coil spring 16 to pass through and be supported on the lower plate 76 with the longitudinal axis of the spring 16 oriented vertically. It will be noted that the spring 16 is transported to the inserter 72 in a fully extended state by any appropriate means of transport (not shown) and is positioned below a compressor 80 which is in vertical alignment with the opening 78 in the top plate 74. The condition of the cloth tube 33 at this point is such that the flap B is positioned to pass under the lower plate 76 of the inserter 72 while the flap A passes under a support plate 82 and has a portion 84. of the edge held on the upper plate 74 of the inserter 72, whereby the flap A is separated from the underlying flap B and an opening is formed between the flaps as best illustrated in Figure 6. The edge portion 84 of the flap A is firmly pressed to the plate 74 by a roller 86. In Figure 7, the spring 16 is shown in a compressed state after activation of the compressor 80.

Figure 8 shows the next step of the process of insertion of the coil spring where the cloth tube 33 is advanced in such a way that the portion 84 of the edge of the flap A moves in register or match or correspondence with a cylinder 88 of air. The insertion of the coil spring is consumed in the schematic view of Figure 9 showing the ram 90 of the air cylinder 88 activated to hold the portion 84 of the edge of the flap A firmly to the top plate 74 of the inserter as a bar 92 of the reciprocating air operated inserter makes the coil spring 16 compressed horizontally from the compressor 80 through the opening formed between the flap A and the flap B to a position in the fabric tube 33 under the flap A as best illustrated in Figure 9. Once the insertion of the coil spring is completed, the cloth tube 33 according to the first form of the invention advances with the coil spring 16 compressed under the support plate 82 to a baffle station designated generally as 94 in FIG. 10. In this station 94, a baffle arm 96 has a free end portion 98 which engages and lifts the flap B to a condition s Realigned offset with respect to the flap A. Figure 11 illustrates the apparatus 100 for carrying out the next step in the process of the first form of this invention, wherein the cloth tube 33 is received by an anvil 102. The anvil 102 can be held by the plate 82 and includes a first upper arm 104 over which the flap B passes. The flap B is pressed firmly into contact with the arm 104 by a second tensioned roller 106. At this stage of the process, the flap A passes under the first arm 104 of the anvil and over the upper part of a second lower arm 108 which is suspended in a cantilevered manner from the first arm 104. The anvil 102 is designed in such a way that the lower arm 108 also projects horizontally in the direction of the apparatus from below the upper arm 104. Turning now to FIG. 12, a first welding station is designated in general by the reference number 110 and includes a cord or 112 ultrasonic welding. In this station 110, the cloth tube 33 has passed through the upper arm 104 of the anvil 102 after which the flap B returns to the coupling superimposed with the flap A, the two flaps are supported by the lower arm 108 of the anvil 102. The welding horn 112 is then activated to place one or more spot welds on the overlap between the flap A and the flap B whereby a superimposed seal is formed. In Figure 13, a second welding station is designated by the reference number 114 and includes a second welding horn 116 which is oriented transversely to the cloth tube 33. In a manner well known in the art, this second welding horn or welding horn 116 is designed to form a linear series of welds spaced between the upper and lower sides of the fabric tube 33 intermediate to successive coil springs 16 to form thereby a series 14 of discrete cloth chambers 18 with the individual coil springs 16 encapsulated within each chamber. Fig. 14 illustrates schematically an operating station 120 of the apparatus comprising a pair of rollers 122 and 124 spaced closely parallel. The rollers 122 and 124 are tensioned together in such a manner that they serve to stretch the cloth tube 33 through the apparatus from the feeding station 30 through all subsequent processing stations of the apparatus. An appropriate recess 126 is formed in one of the rollers 122 or 124 in such a way that the coil springs 16 can freely pass between the rollers 122 and 124. A final forming station according to the first form of the invention is shown schematically in FIG. Fig. 15 and is designated in general by the reference numeral 130. In this station 130 there is provided a rotary beating or striker assembly 132 with resilient arms 134 for striking the cloth tube 33 in the area of the enclosed helical springs 16. This striking action of the kicker 132 causes the coil springs 16 to rotate ninety degrees within their chambers and expand from their compressed state to an extended state, to fill by this the tube or cavity 18. In a second form of the invention, a cloth tube 33 as in the first form of the invention, figure 5, can be initially formed as illustrated in figure 4, wherein the hook 56 guides the loose edge 52 of the fabric 32 to form a flap B which is underlying the flap A. Furthermore, this tube 33 can be advanced through the same process of insertion of the coil spring illustrated in figures 6 -9. However, after the insertion of the helical spring, the tube 33 is advanced directly to the station 140, as illustrated in FIG. 16, where the tube 33 is received by a modified anvil 142 without any deflection of the flap B This anvil 142 has a generally S-shaped configuration with a leg portion 144 that extends over and is supported on the plate 82, such that the anvil 142 is cantilevered from the plate 82. The configuration in S-shape provides an arm portion 146 for holding the flap B of the tube 33a and an arm portion 148 for holding the flap A of the tube 33a. The flap A is pressed firmly into contact with the arm portion 148 by a tension roller 150. At the next station 160, as illustrated in Figure 17, the arm portion 146 of the anvil 142 rejoins the flaps A and B in superposed relation and sustains the superposition for welding by means of the welding horn 112. As in the first forms of the invention, the tube 33 immediately advances to a second welding station 162, as shown in Figure 18, where they form transverse welds through the tube 33 to create cloth chambers. Next, the tube 33 moves through the drive station 164 (FIG. 19) and finally to the striking station 166 (FIG. 20). It can be seen particularly from Figure 20 that the tube 33 in this second form of the invention will finally be assembled with the flap B underlying the flap A and consequently, the flap B could be engaged by the spring 16 as the beater 132 hits the tube 33 to rotate the spring 16 within its respective chamber. While the hitching can be a problem if the striker rotated in a counter-clockwise direction as seen in Figure 20, in practice, by rotating the striker in relation to the hands of the clock, the bottom of the wharf 16 will move along the lower surface 62 of the tube 33 as the spring 16 is reoriented. By this, the spring 16 remains separated from the leading edge 168 of the flap B and the engagement of the flap B is not present.

It can now be appreciated that the apparatus of the present invention is highly efficient and effective in constructing series of enclosed coil springs having a seal formed along one side thereof, instead of having a seal adjacent to the ends of the coils. springs. A series of coil springs 170 enclosed in fabric, constructed in accordance with the present invention is illustrated in side view in FIG. 21. As seen therein, a flat overlapping side seam 172 eliminates the two upper flaps 28 of FIG. series 14 of the prior art shown in Figure 2. Thus, the series 170 of coil springs is highly desirable for use in an internal mattress spring assembly in such a manner as to eliminate objectionable false fluffing. It can also be appreciated that because the side seam 172 can be overlapped by only about 1.27 cm (one-half inch), savings can be made in the fabric 32 with respect to prior art constructions having two flaps 28 in excess. In addition, the apparatus of the present invention can be easily configured from existing known equipment with the addition and / or replacement of a few parts and sub-assemblies. Thus, the invention lends itself to a highly economic update of the equipment currently in use. Although series 170 is shown with weld 174 disposed along the upper side of the seam or joint 172 in Figure 29, it can be appreciated that if this series 170 were constructed in accordance with the first form described above of the invention, the corresponding series 170 constructed in accordance with the second form of the invention will simply differ only in that the weld 174 will be on the opposite side of the seam or joint 172 as the series 170 leaves the apparatus. Furthermore, it can be seen that while welds 174 are illustrated by discrete points, as they are formed in the fabric 32 along the seam or joint 172, linear welds can be easily worn along the seam or seam. 172 if a more positive seal or seam 172 is considered desirable. While the present invention has been described in connection with preferred embodiments thereof, it will be understood by those skilled in the art that many changes and modifications can be made without deviating from the true spirit and scope of the invention. Thus, it is proposed by the appended claims to cover all such changes and modifications in the true spirit and scope of the present invention. It is noted that, in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (22)

1. Claims Having described the invention as above, the content of the following is claimed as property: 1. An apparatus for constructing series of helical springs wherein each of the coil springs is enclosed within individual chambers or fabric cavities having seams or stitches. flat superimposed side seams, characterized in that it comprises: a fabric feeding mechanism having means for folding a flat ribbon of cloth a first time to define a first flap and means for folding the belt a second time to define a second underlying flap the first flap, to define by this a cloth tube having a flap side and a back side; means for separating the first flap from the second underlying flap to form an opening between the flaps; a helical spring inserter structured and sized to insert a compressed coil spring through the opening to the cloth tube; means for closing the opening with the second flap underlying the first flap on the cloth tube, and with the compressed coil spring enclosed within the tube; means for interconnecting the first and second closed flaps.
2. 2. The apparatus according to claim 1, characterized in that the closing means includes a deflector arm for engaging the second underlying flap and flexing it back to the superposed relation with the first flap. The apparatus according to claim 1, characterized in that the feeding mechanism of the fabric includes a diamond-shaped plate to create a first fold in the fabric belt. 4. The apparatus in accordance with the claim 3, characterized in that the fabric feeding mechanism includes a hook element structured and sized to create a second fold in the fabric belt. The apparatus according to claim 4, characterized in that the first fold creates a first flap, the second fold creates a second flap and the hook element is configured to place the second flap under the first flap. 6. The apparatus according to claim 4, characterized in that the hook element rotates inversely one edge of the belt to create the second fold. The apparatus according to claim 1, characterized in that it includes means for forming seams or transverse joints between the enclosed helical springs to create individual discrete chambers or cavities to accommodate the springs. The apparatus according to claim 7, characterized in that the means for forming seams or transverse joints between the enclosed coil springs comprise a device for welding. The apparatus according to claim 1, characterized in that it includes a striker assembly for striking the compressed coiled coil springs to rotate them in the fabric chambers or cavities and to cause the coil springs to expand longitudinally from the compressed state. 10. The apparatus in accordance with the claim I, characterized in that the helical spring is compressed along an axis oriented at right angles to the longitudinal axis of the cloth tube and the helical spring is inserted transversely to the longitudinal axis of the cloth tube. The apparatus according to claim 1, characterized in that the inserter of the coil spring includes a pair of parallel spaced plates. 12. The apparatus in accordance with the claim II, characterized in that a first of the plates includes an opening, which is structured and dimensioned to allow the spring to be compressed through the opening in the plate. The apparatus according to claim 11, characterized in that it includes a reciprocating rod disposed between the plates for pushing the coil spring compressed outwardly of the coil spring inserter and the cloth tube. 14. The apparatus according to claim 1, characterized in that the means for interconnecting the first and second flaps comprise a welding device. 15. The apparatus according to claim 14, characterized in that the welding device is an ultrasonic welder. 16. A method for forming a series of coil springs wherein each of the coil springs is enclosed within a single cloth chamber having flat overlapping side seams or joints, the method is characterized in that it comprises the steps of: folding a elongated ribbon of the fabric for the first time to create a first flap that extends longitudinally; folding the fabric ribbon for a second time to create a second flap extending longitudinally, underlying the first flap laterally, to thereby define a fabric tube having a flap side and a back side, with the first flap on the side of the flap that is laterally superimposed on the second flap on the side of the flap; transporting the fabric tube longitudinally through a spring inserter in such a way that the spring inserter separates the overlapping flaps to thereby form an opening extending laterally in the tube; insertion of a compressed coil spring into the opening in the tube; transporting the fabric tube to an anvil and thereby closing the opening in the tube with the first flap superimposed laterally on the second flap; and interconnecting the first and second flaps superimposed laterally to form a seal superposed therebetween. 17. The method of compliance with the claim 16, characterized in that it includes the step of forming transverse seams or seams between the coil springs to create discrete individual chambers or cavities to accommodate the springs. 18. The method of compliance with the claim 17, characterized in that the first flap is created by passing the cloth tape over the edges of a diamond-shaped folding plate. The method according to claim 17, characterized in that the second flap is created by reversely rotating an edge of the belt around a hook element. The method according to claim 17, characterized in that the helical spring is compressed along an axis oriented at right angles to the longitudinal axis of the cloth tube and the helical spring is inserted transversely to the longitudinal axis of the cloth tube. The method according to claim 17, characterized in that it includes the additional step of rotating the compressed coil spring inside the chamber or cavity to allow the coil spring to expand within the chamber. 22. The method according to claim 17, characterized in that the closing step includes redefining the second flap from below the first flap to re-superimpose the relation with the first flap.