Pocket spring mattress and method for manufacturing a spring mattress

Abstract

A pocket spring mattress for use in bedding or sheeting products is disclosed. The mattress comprises a plurality of interconnected coil springs housed within a continuous cover forming strings of pockets for receiving the coil springs. Adjacent coil springs in each string are spaced apart by an interleaving separation distance that is at least 20 percent greater than the diameter of the largest helical winding of adjacent coil springs. The pocket spring mattress further comprises a cushion pad positioned above an upper end of each coil spring, the cover defining a first compartment for housing the coil spring and a second compartment for housing the cushion pad, the first and second compartments being separated from each other. Each cushion pad has an extension length in the longitudinal direction of the string that exceeds the diameter of the largest helical winding of the corresponding coil spring.

Description

Technical Field

[0001] The present invention relates to a type of spring mattress in which springs are housed within a cover, known as a pocket spring mattress, and a method for manufacturing this type of mattress.

Background Art

[0002] One common technique for manufacturing spring mattresses is a technique known as pocket technology. According to this technique, the springs are housed within pockets, that is, the springs are individually housed by a cover material. With this configuration, the springs become relatively individually elastic, and thereby the load is more evenly distributed over the entire surface receiving the load, so that each spring can bend separately without affecting adjacent springs, and as a result, the comfort of the user is improved.

[0003] However, one problem inherent in this type of mattress is that its manufacturing cost is very high compared to many other types of spring mattresses. A solution to this problem has been previously proposed by the same applicant in U.S. Patent No. 7,048,263. The mattress disclosed in this specification is a pocket mattress in which coil springs are further separated from each other than in a conventional pocket spring mattress by providing two separate lateral connection lines between pairs of adjacent coil springs. This significantly reduces the density of the springs in the mattress and reduces the manufacturing cost of the mattress. At the same time, surprisingly, it has been found that the overall comfort of the mattress is not adversely affected by this reduction in spring density.

[0004] However, the construction of beds and sheets using this type of mattress remains relatively difficult and costly to manufacture. It is necessary to reliably maintain increased mattress separation distance, and therefore, the outer edge of the mattress needs to be attached to a rigid frame, such as a steel frame, to secure it to the bed base. Furthermore, to provide good comfort, it is often necessary to include one or more upholstered layers, such as foam or cloth, to create a flat and comfortable surface. Such upholstered layers complicate and increase the cost of mattress / bed manufacturing, and also reduce the inherent individual resilience and comfort of the pocket spring core.

[0005] Therefore, there remains a need for improved pocket spring mattresses that provide the same or even improved levels of comfort, but are more cost-effective to manufacture and use. There is also a need for coil springs and pocket spring mattresses with individual pockets that provide improved resilience and responsiveness, and reduce the amount of cushioning or padding material used on top of the bedding or sheet product once the spring assembly is complete. Furthermore, there is a need for coil springs and pocket spring mattresses with individual pockets that are more robust and maintain their properties over long periods and extended use. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent No. 7048263 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a pocket spring mattress of the type defined in the introduction, and a method for manufacturing such a mattress, thereby mitigating at least partially the disadvantages mentioned above. [Means for solving the problem]

[0008] This objective is achieved by the pocket spring mattress and the method for manufacturing the mattress as defined in the attached claims.

[0009] According to a first aspect of the present invention, a pocket spring mattress for use in bedding or sheet products is provided, comprising a plurality of interconnected coil springs housed within a continuous cover forming a string of pockets for receiving coil springs, wherein the coil springs within each string are separated by transverse connecting lines, a plurality of such strings are arranged parallel to each other and connected to each other, adjacent coil springs within each string are spaced apart by an inter-insertion separation distance, the separation distance exceeding at least 20 percent of the diameter of the largest helical winding of the adjacent coil springs, each coil spring having an upper end and a lower end, the pocket spring mattress further comprising a cushion pad positioned above the upper end of each coil spring, the cover providing a first compartment for housing the coil springs and a second compartment for housing the cushion pad, the first and second compartments being separated from each other, and each cushion pad having an extending length in the longitudinal direction of the string exceeding the diameter of the largest helical winding of the corresponding coil spring. Therefore, two compartments form a pocket unit, in which case the compartments are arranged to overlap each other, and multiple such pocket units are distributed in the width and length directions of the mattress.

[0010] In this application, "corresponding coil spring" means a coil spring over which any particular cushion pad is placed, i.e., a coil spring located within the same pocket unit as the cushion pad.

[0011] The isolation of the coil springs within the string is achieved here in the same manner as in the aforementioned U.S. Patent No. 7,048,263, which is incorporated in its entirety by reference. However, in contrast to the known solutions described above, providing cushion pads in a dedicated, integrated compartment located above each coil spring and across the compartments that receive the coil springs yields several very surprising advantages.

[0012] Widening the spacing between coil springs allows mattresses to be manufactured more easily and at a lower cost, and also improves circulation and ventilation. Furthermore, it has been found that the larger spacing does not affect the mattress's properties or comfort, and is equivalent to or even better than conventional pocket spring mattresses.

[0013] The use of cushion pads incorporated into pocket spring mattresses is itself known from U.S. Patent Application Publication No. 2016 / 045034 by the same applicant, which is incorporated into this application by reference in its entirety. However, in this invention, the cushion pads are positioned and arranged over the perfectly isolated coil springs. Furthermore, the cushion pads are given a length in the length direction of the string that exceeds the diameter of the largest helical winding of the coil springs. The cushion pads are also firmly fixed to the coil springs by being provided in separate compartments formed in the string. Thus, the position of the cushion pads is always firmly and reliably maintained, and the extended length of the cushion pads maintains the separation between the coil springs in the string. As a result, in this new type of mattress, a steel frame and other complex and expensive means are no longer required to maintain the separation of the coil springs. Instead, the large cushion pads spread across the surface of the mattress, thereby effectively maintaining the coil springs located below in the intended perfectly isolated position.

[0014] Furthermore, by providing at least one cushion pad within each individual pocket, each coil spring functions independently, resulting in a more comfortable bedding or sheet product. This maintains the individual elasticity of the coil springs within the pocket, providing superior comfort and pressure distribution.

[0015] Furthermore, in this novel type of pocket spring mattress, the cushion pad is already incorporated into each pocket unit, eliminating the need for additional padding layers. Moreover, because very large cushion pads are used, they spread across the top surface of the mattress, thereby creating a flat, highly uniform, yet individually resilient top surface. This reduces the need for upholstery layers, and the mattress may be used, for example, without any upholstery layer at all, or with only a thin layer of fabric or cloth. Consequently, the use of mattresses in forming mattresses, bed structures, and seat products becomes even more cost-effective while simultaneously enhancing user comfort.

[0016] Furthermore, the manufacture of this novel type of pocket spring mattress is relatively simple and cost-effective because, for example, it is not necessary to directly connect the cushion pads to the coil springs. Instead, the cushion pads are placed in separate compartments located above the pockets that house the coil springs. This allows for the use of conventional manufacturing processes to form the pocket mattress, while also easily adding separate compartments above each pocket unit to incorporate the cushion pads. As a result, the present invention is highly useful for automated and cost-effective manufacturing, and it is also relatively easy to incorporate the further step of providing separate compartments for the cushion pads and inserting such cushion pads into the compartments using already known and well-established manufacturing processes and equipment.

[0017] Furthermore, the fact that the coil springs and cushion pads within each pocket unit are separated from each other and placed in separate compartments ensures that the cushion pads always remain in place. The casing material of the compartments containing the coil springs prevents the cushion pads from shifting during use. As a result, the appearance and comfort of the mattress are maintained over a long period of use, thereby resulting in a long-lasting product.

[0018] The novel pocket spring mattress can be used in a variety of bed and seat structures. For example, this novel pocket spring mattress may be used in a bed or seat structure where the mattress must be expandable between, for example, an extended state for sleeping, where the mattress area is larger and the spring density is lower, and a contracted state for sitting, where the mattress area is smaller and the spring density is higher. Such mattresses are known in themselves and are very useful in vehicles, for example, large trucks / trucks. Such expandable / contractable mattresses and bed / seat structures are known in themselves, for example, U.S. Patent Application Publication No. 2017 / 086597, U.S. Patent No. 8176589, U.S. Patent No. 8635727, and U.S. Patent No. 9554656, all of which are by the same applicant and are incorporated in whole by reference. The use of the mattress of the present invention in such expandable / contractable bed / seat structures provides additional remarkable advantages. Because cushion pads are generally elastically compressible, the surface of the mattress remains flat and smooth in both the expanded and contracted states. Furthermore, due to their elasticity, the cushion pads provide a force that moves the mattress from the compressed to the expanded state. This facilitates the transition from the compressed to the expanded state and ensures that the springs and pockets remain uniformly distributed at all times in the contracted, expanded, and any intermediate states between them.

[0019] The separation distance between adjacent coil springs may be given in various ways. In one alternative, the transverse connecting line has a width in the longitudinal direction of the strip that forms the separation distance. Thus, the transverse connecting line may consist of a solid, broad, continuous connecting line, or it may instead consist of a line formed from separate elements arranged following each other along a relatively broad range of connecting lines such as rectangles, circles, or ellipses. As another alternative, the separation distance may be given by two preferably parallel transverse connecting lines provided between adjacent coil springs, which are spaced apart in the longitudinal direction of the string to form the separation distance. The connecting lines may be formed by ultrasonic welding, stitching, clamping, bonding, or any other suitable embodiment.

[0020] The cover material forming the two compartments may comprise a first fabric piece forming the first compartment and a second fabric piece forming the second compartment. Thus, the first fabric piece may be used in a conventional manner to provide strings of individually pocketed coil springs, and the second fabric piece may then be added during or after the formation of the first fabric strings to provide further compartments for accommodating cushion pads.

[0021] Preferably, the first fabric piece is arranged to completely house the coil spring, and the second fabric piece is arranged to partially house the first compartment and be fixed to the first fabric piece. Thus, the first fabric piece may be arranged to completely surround the coil spring and form the first compartment itself, while the second fabric piece may be arranged to partially surround the cushion pad. For this purpose, the second fabric may have two ends, each connected to the first fabric on the opposite side of the string. In this embodiment, the second compartment is formed by the second fabric forming the upper and side walls of the compartment and the first fabric forming the lower wall of the compartment.

[0022] In a preferred embodiment, the second fabric piece is fixed to the first fabric piece along a number of transverse connection lines extending parallel to the longitudinal direction of the coil spring, the connection lines preferably consisting of surface joints such as adhesive or welding. This allows the connection of the second fabric piece to be easily incorporated into conventional pocket spring manufacturing processes.

[0023] In this embodiment, the first fabric may be provided with first lateral connection lines that form an inter-insertion separation distance between coil springs, such as by using two parallel, separated first lateral connection lines between each pair of adjacent springs. Furthermore, the second fabric may be provided with narrower second lateral connection lines, such as a narrow single second lateral connection line, between each pair of adjacent cushion pads, so that the cushion pads are positioned close to each other with no separation distance or only a very small separation distance between them.

[0024] In this embodiment, the second fabric may be connected to the first fabric via a first transverse connection line by extending a connection line through both the first and second fabrics in the region where the first and second fabrics overlap. Alternatively, the second fabric may be connected to the first fabric via a second transverse connection line by extending a connection line through both the first and second fabrics in the region where the first and second fabrics overlap. Alternatively, a separate connection may be made between the first and second fabrics. Such a separate connection may be located across the first and / or second transverse connection lines or adjacent to the first and / or second transverse connection lines.

[0025] Preferably, the second fabric is attached to the first fabric only by connection points or connection lines formed by the first and / or second lateral connection lines or extending over or adjacent to the first and / or second lateral connection lines. However, alternatively or in addition thereto, connection points or connection lines may be provided between the first fabric and the second fabric at other locations, such as in the center between lateral connection lines that form each pocket, i.e., located over the coil springs.

[0026] However, as another method instead of forming two compartment rooms by two separate fabric pieces, the first compartment room and the second compartment room may be formed by a single fabric piece. For example, as disclosed in U.S. Patent No. 6,397,418 by the same applicant, the fabric can be arranged in an S shape to form separate compartment rooms, and the entire disclosure of which document is incorporated herein by reference.

[0027] Similar to the first embodiment described above, in this embodiment as well, between each pair of adjacent cushion pads, the cushion pads are arranged close to each other without any separation distance between the cushion pads or with only a very small separation distance. For example, by using two parallel and separated first lateral connection lines between each pair of adjacent springs and a narrower second lateral connection line such as a narrow single second lateral connection line, a first lateral connection line forming an interposed separation distance between the coil springs may be provided. Further, the free ends of the single fabric piece may be connected to each other in the overlapping area by the first and / or second lateral connection lines or, alternatively or in addition thereto, by separate connections.

[0028] Regardless of whether the cell compartments are formed by a single fabric or by two fabrics, each pocket unit may here be regarded as two upper located cell compartments formed by a common outer cover surrounding both cell compartments and a common partition wall connected to or integrated with the outer cover and extending between the coil spring and the cushion pad to separate the two cell compartments.

[0029] The extension of the partition wall between the joints to the outer cover preferably exceeds that of the lateral dimension of the coil spring, i.e., exceeds the diameter of the largest coil winding / turn. This may be achieved, for example, by connecting the second fabric to the first fabric such that the extension of the first fabric, which forms the partition wall, extends between these connections to the second fabric and exceeds the diameter of the coil spring. With this configuration, the portion of the partition wall where the spring and the cushion pad abut can move between the upper end position and the lower end position without affecting the outer cover in the joint region of the partition wall to the outer cover. In this way, each pair of spring and cushion pad can bend individually between these end positions within the extension region within the pocket. Such a configuration of the partition wall movable between the upper end position and the lower end position is itself known from U.S. Patent No. 6,397,418 by the same applicant, and the said document is hereby incorporated in its entirety by reference into the present application.

[0030] The dimensions of the pocket, i.e., the outer cover, the coil spring, and the cushion pad, are preferably such that the coil spring is maintained in a biased state, and in this case, the partition wall is maintained in the upper end position when no external pressure is applied. Thereby, the pocket unit becomes even more independently elastic.

[0031] However, when the pocket unit is not biased, the partition wall can be maintained between the upper and lower end positions. Such a configuration ensures that the overall dimensions of the pocket unit are maintained even if the dimensions of the cushion pad change during use. For example, it is common for this type of cushion pad to lose some of its initial shape, such as some of its initial thickness, during use. However, this is compensated for when the biased coil spring and partition wall are not in the uppermost position, and the top surface of the pocket unit and mattress is maintained in the same shape and position. Thus, a mattress with such a pocket unit maintains its smooth and uniform top surface, and as a result maintains its original appearance, even after a considerable period of use and even when some deterioration of the cushion pad has occurred.

[0032] Each coil spring preferably comprises an upper end winding section, a lower end winding section, and a plurality of spiral sections between the upper and lower end winding sections. Preferably, the coil spring comprises 2 to 10 spiral sections, most preferably 5 to 8 spiral sections.

[0033] On the mattress side, opposite the cushion pad, a stabilizing sheet may be connected to the strings. This stabilizing sheet is preferably made of a flexible material and may consist of a fabric such as a nonwoven fabric, and preferably extends across the entire surface of the mattress. The sheet may be connected to the bottom side of the strings by adhesive, welding, etc. This helps the stabilizing sheet stabilize the mattress on the side opposite the cushion pad and maintain the coil springs in an upright, isolated position.

[0034] However, the pocket spring mattress may instead further include a second cushion pad located below the lower end of each coil spring. Such a second cushion pad may be placed in a third compartment formed in the string, which is separated from the first and second compartments. Thus, each pocket unit accommodates two cushion pads, one above and one below the end winding of the coil spring. This provides cushion pads on both sides of the mattress, thereby allowing the mattress to be used with both sides facing upwards. The cushion pads at both ends may be identical or similar, thereby providing equal characteristics on both sides. This extends the lifespan of the pocket unit and the mattress. However, the cushion pads can also be different, thereby giving the user a choice between different characteristics by choosing which side should be used as the upper side. The second cushion pad also preferably has an extending length in the longitudinal direction of the string that exceeds the diameter of the largest helical winding of the corresponding coil spring.

[0035] When forming the spring string, the longitudinal edges of the fabric strips are joined to each other by longitudinal attachment lines in any known manner, such as sewing, welding, or bonding, once the fabric strips have been wrapped around the aligned rows of coil springs. Opposing plies of the fabric strips on the opposite side of the coil springs are joined to each other between the coil springs by transverse attachment lines, which may similarly be ultrasonic welding, sewing lines, or adhesive lines, or by other means of attaching the plies to each other. Further compartments for accommodating cushion pads may be provided by using further fabric pieces or by wrapping the same fabric to create further compartments. The fabric strips preferably further comprise at least one longitudinal connection line extending parallel to the longitudinal direction of the string, which, together with a plurality of transverse connection lines extending transversely to the longitudinal direction of the string, defines the pocket.

[0036] A cushion pad may include at least one foam piece, preferably made of urethane or latex. One or more cushion pads may also include a cloth piece fixed to the foam piece. For example, a cushion pad may be a urethane or latex foam piece, and may be optionally sandwiched between one or two cloth pieces. However, a cushion pad may comprise multiple foam pieces. In addition to foam, other materials such as memory foam, gel, or cotton may be used to form the cushion pad.

[0037] In one embodiment, the cushion pad includes a layered structure comprising a flexible foam arranged in a sandwich configuration with a rigid foam. In this configuration, it is preferable that the flexible foam is positioned on top of the rigid foam such that the flexible foam faces the upper mattress surface and the rigid foam faces the coil springs.

[0038] The cushion pads may have an extended width in the width direction of the string, in which case the extended width is smaller than the extended length, and the extended width is preferably approximately equal to the diameter of the largest helical winding of the coil spring. However, instead, the extended width of each cushion pad may exceed the diameter of the largest helical winding of the corresponding coil spring.

[0039] The extended length of the cushion pad is preferably at least 15%, preferably at least 20%, of the diameter of the largest helical winding of the corresponding coil spring. Most preferably, the extended length of the cushion pad is at least 75-100%, more preferably 80-100%, and most preferably 90-100%, of the inter-coil spring separation distance, of the diameter of the largest helical winding of the corresponding coil spring.

[0040] The spacing between coil springs is greater than 25 percent, preferably greater than 30 percent, and most preferably greater than 50 percent, of the diameter of the largest helical winding of the adjacent springs.

[0041] The spacing distance between coil springs is preferably greater than 2 cm, more preferably greater than 4 cm, and most preferably greater than 6 cm.

[0042] The cushion pad preferably has an extension length in the longitudinal direction of the string that exceeds at least 15%, preferably at least 20%, more preferably at least 25%, and most preferably at least 50% of the diameter of the largest helical winding of the corresponding coil spring.

[0043] The cushion pad preferably has an extension length in the longitudinal direction of the string such that the diameter of the largest helical winding of the corresponding coil spring exceeds at least 2 cm, more preferably at least 3 cm, and more preferably at least 5 cm.

[0044] The mattress according to the present invention is particularly preferably having a spring density of less than 15 springs / meter, preferably less than 13 springs / meter, in at least one longitudinal direction where separation distance is given. The resulting mattress is generally much simpler and less expensive than conventional mattresses which have 30 or more springs in the longitudinal direction of the mattress.

[0045] The cushion pads are preferably positioned on top of the coil springs such that they extend from the corresponding coil springs in the longitudinal direction of the string. Preferably, the cushion pads are positioned essentially concentrated over each corresponding coil spring, so that they extend from the coil springs on both sides with approximately the same length in both the length and width directions of the string. This improves the support provided by the cushion pads, especially between coil springs with an interlocking distance, thereby resulting in a more comfortable mattress.

[0046] In one embodiment, the cushion pad has a substantially rectangular shape, preferably with chamfered or rounded corners. This allows the cushion pad to cover almost the entire top surface of the mattress. However, instead, the cushion pad may have a circular, hexagonal, or octagonal shape, and many other geometric configurations are also achievable.

[0047] It is preferable that the casing be formed from a weldable woven material.

[0048] Parallel strings are preferably arranged side by side and interconnected by surface adhesion between contact surfaces, in which case the surface adhesion that interconnects the strings preferably includes at least one of bonding and welding. However, other conventional fasteners such as hog rings may be used.

[0049] The spacing distance between coil springs reduces the compactness of the mattress, thereby reducing the number of springs required and simplifying operations such as housing the springs within the cover. Consequently, the mattress becomes easier and cheaper to manufacture. However, surprisingly, the mattress properties are not significantly affected by the reduction in compactness, and it has been found that the mattress of this invention provides nearly the same quality of comfort as conventional pocket spring mattresses. In fact, because each individual spring can support the load relatively independently, it has even been found that, in some cases, increasing the distance between springs increases the individual elasticity of the springs, thereby improving comfort. At the same time, the large cushioning pad provides the mattress with a smooth, comfortable, and relatively dense top surface.

[0050] According to another aspect of the present invention, a method for manufacturing a spring mattress of the type comprising a plurality of interconnected coil springs housed within a continuous cover that forms a string of pockets for receiving coil springs, The steps include housing the spring within a continuous cover material, The steps include forming pockets in a continuous cover material by providing lateral connection lines between adjacent coil springs, The steps involve interconnecting several strings with one another, Includes, A method is provided in which adjacent coil springs within each string are spaced apart by an inter-insertion separation distance, the separation distance exceeding at least 25 percent of the diameter of the largest helical winding of the adjacent coil springs, each coil spring having an upper end and a lower end, and a cushion pad being provided above the upper end of each coil spring, wherein the cover provides a first compartment for housing the coil springs and a second compartment for housing the cushion pad, the first and second compartments being separated from each other, and the cushion pad having an extending length in the longitudinal direction of the string exceeding the diameter of the largest helical winding of the corresponding coil spring.

[0051] In particular, the order of the previously defined method steps may differ. For example, the spring housing and cushion pad housing may be performed in any order in an automated manufacturing procedure, or they may be performed simultaneously. Furthermore, the connection lines may be provided in any order, or they may be provided simultaneously.

[0052] According to this embodiment, the same advantages and specific features as those described above in relation to the first embodiment can be obtained. Furthermore, the advantages and embodiments of the present invention will become apparent from the following detailed description of the invention.

[0053] Herein, these and other aspects of the present invention will be described in more detail with reference to the accompanying drawings illustrating embodiments of the present invention. [Brief explanation of the drawing]

[0054] [Figure 1] A schematic perspective view of one embodiment of a mattress according to one embodiment of the present invention is shown. [Figure 2] This shows a cross-sectional view of individually pocketed coil springs according to the first embodiment of the present invention. [Figure 3] This shows a cross-sectional view of individually pocketed coil springs according to a second embodiment of the present invention. [Figure 4] This is a side view of a part of a string relating to one embodiment of the present invention. [Figure 5] Figure 4 is a top view of the string. [Figure 6] Figure 2 is a schematic partial cross-sectional perspective view illustrating various method steps for manufacturing individually pocketed coil springs. [Figure 7a] Figure 3 is a schematic perspective view showing various method steps for manufacturing individually pocketed coil springs. [Figure 7b] Figure 3 is a schematic perspective view showing various method steps for manufacturing individually pocketed coil springs. [Figure 8] A portion of a string equipped with a separated spring according to one embodiment of the present invention is shown. [Figure 9] A portion of a string comprising a separated spring according to another embodiment of the present invention is shown. [Figure 10] This is a schematic diagram showing a manufacturing apparatus to be used in conjunction with the method shown in Figure 7. [Figure 11] This is a partial top view of a mattress according to another embodiment of the present invention, in which the strings are arranged in a staggered pattern. [Figure 12] This is a cross-sectional view of a coil spring individually placed in a pocket according to a further embodiment of the present invention. [Modes for carrying out the invention]

[0055] Referring to Figures 1 to 10, a mattress 1 embodying the invention of this application is shown. Although a mattress is shown, the present invention may be used to constitute any bedding or sheet product. The mattress 1 comprises a plurality of individually pocketed coil spring units 2.

[0056] Here, the mattress 1 is formed from a plurality of parallel strings 3 of individually pocketed coil spring units 2. Each string 3 of the pocketed coil springs 2 preferably comprises a cloth-covered or fabric strip 31 in which aligned coil springs in a transverse or vertical row are located. Each individual pocket is formed here, for example, by longitudinal connecting lines 32 extending along the string at the top or in the middle of the string, and by transverse connecting lines 33 extending axially along the spring. The strings 3 of adjacent springs may be fixed to each other by surface adhesion on adjacent surfaces, such as by adhesive, ultrasonic welding, hog ringing, or any other means.

[0057] In the embodiments described above, the individually pocketed coil spring units are arranged as a continuous string, aligned side by side, and parallel to each other, extending in the width or length direction of the mattress or any other spring assembly. However, several other configurations are possible. For example, the string may be non-linear, such as having a meandering shape. Furthermore, the individually pocketed coil spring units may be provided as single units or as shorter strings consisting of only a few individually pocketed coil springs.

[0058] As is best seen in Figures 2 to 4, each individually pocketed coil spring unit is provided with a casing 31, which forms a pocket and provides a first compartment 21 for housing the coil spring 4 and a second compartment 22 for housing the cushion pad 5. The first and second compartments are separated from each other. Each coil spring has an upper end 41 and a lower end 42. The second compartment 22 is positioned above the first compartment 21, thereby positioning the cushion pad 5 above the upper end 41 of the coil spring 4. Thus, the cushion pad can be maintained in place simply by being housed within the compartments without requiring any further fastening.

[0059] Adjacent coil springs within each string are spaced apart by an inter-insertion distance exceeding at least 25 percent of the diameter of the largest helical section of the adjacent coil springs. Furthermore, each cushion pad located above the upper end of each coil spring in a separate compartment of the pocket casing has an extension length in the longitudinal direction of the string that exceeds the diameter of the largest helical section of the corresponding coil spring. This allows the cushion pads to fill the gaps formed between the springs, thereby maintaining the separation distance between the springs and providing a smooth top surface for the mattress.

[0060] The separation distance between adjacent coil springs may be given in various ways. In one alternative, the lateral connection line has a width in the length direction of the strip that forms the separation distance. Thus, the lateral connection line may consist of a solid, broad, continuous connection line, or instead, a line formed from separate elements arranged following each other along a relatively broad range of connection lines such as rectangles, circles, or ellipses. Such an embodiment is shown in Figure 9, in which a broad lateral connection line 33' is provided, which is formed as a discontinuous line.

[0061] Alternatively, the separation distance may be provided by two preferably parallel transverse connecting lines provided between adjacent coil springs, which are spaced apart longitudinally in the string to form the separation distance. The connecting lines may be formed by ultrasonic welding, stitching, clamping, bonding, or any other suitable embodiment. These connecting lines may also be formed as continuous or discontinuous lines, including points, short lines, rectangles, etc. Such an embodiment is shown in Figure 8, in which two separated connecting lines 33a, 33b are provided between each pair of adjacent coil springs 31 in each string.

[0062] The connection line may be achieved by joining the cover materials together on both sides of the string by welding, either as continuous welding or as spot welding. Alternatively, one or more interconnecting elements may be provided to join the cover materials together, such as one or more stitched seams or clamps.

[0063] These separation distances are preferably located between substantially all springs in the longitudinal direction of the string, which may be in the longitudinal direction of the mattress or the width direction.

[0064] The cushion pad may have an extended width in the width direction of the string, in which case the extended width is smaller than the extended length. The extended width may be approximately equal to the diameter of the largest helical winding of the coil spring, for example. However, instead, the extended width of each cushion pad may exceed the diameter of the largest helical winding of the corresponding coil spring.

[0065] The extended length of the cushion pad is preferably at least 20% greater than the diameter of the largest helical section of the corresponding coil spring. Most preferably, the extended length of the cushion pad is greater than 75-100%, more preferably 80-100%, and most preferably 90-100% of the spacing distance between the coil springs, compared to the diameter of the largest helical section of the corresponding coil spring.

[0066] The spacing distance between coil springs is preferably greater than 2 cm, more preferably greater than 4 cm, and most preferably greater than 6 cm.

[0067] The cushion pad preferably has an extension length in the longitudinal direction of the string that exceeds at least 15%, preferably at least 20%, more preferably at least 25%, and most preferably at least 50% of the diameter of the largest helical winding of the corresponding coil spring.

[0068] The mattress according to the present invention is particularly preferably having a spring density of less than 15 springs / meter, preferably less than 13 springs / meter, in at least one longitudinal direction where separation distance is given. The resulting mattress is generally much simpler and less expensive than conventional mattresses which have 30 or more springs in the longitudinal direction of the mattress.

[0069] The cushion pads are preferably positioned on top of the coil springs such that they extend from the corresponding coil springs in the longitudinal direction of the string. Preferably, the cushion pads are positioned essentially concentrated over each corresponding coil spring, so that they extend from the coil springs on both sides with approximately the same length in both the length and width directions of the string. This improves the support provided by the cushion pads, especially between coil springs with an interlocking distance, thereby resulting in a more comfortable mattress.

[0070] Each pocket unit has at least two compartments, one for housing a coil spring and the other for receiving a cushion pad on one side of the mattress. However, it is also possible to have three or more compartments. For example, individually pocketed coil spring units may have compartments for housing cushion pads at both the upper and lower ends of the coil spring. This would provide cushion pads on both sides of the mattress.

[0071] A coil spring preferably comprises an upper end winding section, a lower end winding section, and a plurality of spiral sections between the upper and lower end winding sections. Preferably, a coil spring comprises 2 to 10 spiral sections, most preferably 5 to 8 spiral sections.

[0072] Each casing / pocket contains at least one, preferably just one, helical coil spring. The spring may have a helical winding section with a diameter of about 2 to 10 cm, preferably about 6 cm. Preferably, the coil spring is barrel-shaped and has an upper and lower winding section having a smaller diameter than the central winding section of the spring. However, instead, the winding sections may all have the same diameter, or they may have other variations in diameter. For example, the coil spring may take the form of an hourglass-shaped coil spring or any other shape of spring.

[0073] The height of the cushion pad is preferably about the same as the height of the coil spring. The height of the cushion pad is preferably in the range of 2 to 10 cm, preferably in the range of 3 to 7 cm, and most preferably in the range of 5 to 6 cm. The height of the coil spring is preferably in the range of 50 to 100% of the height of the corresponding coil spring, preferably in the range of 50 to 90% of the height of the corresponding coil spring, and most preferably in the range of 60 to 80%.

[0074] The cushion pad may be formed from a single material or from several different materials. For example, the cushion pad may have a layered structure comprising, for example, a foam core, an upper fabric piece, and a lower fabric piece. The upper and lower fabric pieces may be bonded to the upper and lower surfaces of the foam core, or otherwise fixed. Alternatively, the cushion pad may comprise one or more foam pieces, with or without fabric pieces. The foam pieces may be formed from polyurethane, latex, or any other conventional foaming material. Alternatively, a pad made of cotton or any other material may be used. A pad such as a gel, optionally housed within an outer shell, may be used.

[0075] The cushion pad is shown to be roughly rectangular with rounded or chamfered corners, but it may instead be any other shape or form, such as elliptical, square, or any other desired shape. Similarly, the height of the cushion pad may be varied as deemed appropriate and suitable for any particular application.

[0076] Different cushion pads and / or coil springs may be used in different coil spring units, each individually pocketed, to impart various properties to different parts of the mattress. This may be used, for example, to form areas of the mattress with different characteristics.

[0077] As shown in Figure 1, the mattress 1 has a substantially flat upper surface formed by individually elastic cushion pads.

[0078] The compartments within the casing may be provided in various ways, and two typical embodiments are shown in Figures 2 and 3.

[0079] In the embodiment shown in Figure 2, the first and second compartments are formed by a single piece of fabric. The casing material is arranged in an S-shape to form separate compartments in a manner similar to that disclosed in U.S. Patent No. 6,397,418 and International Publication No. 2014 / 166927 by the same applicant, the aforementioned documents being incorporated in their entirety by reference. The first portion of the casing material forms the first compartment 21, and the compartment is closed by a longitudinal connection line 32 located on the side of the unit. A portion of the material extends beyond the longitudinal connection line 32 and returns toward the other side of the unit, where it is connected to the side of the first compartment 21 by a second longitudinal connection line 34. This forms the second compartment 22 above the first compartment 21.

[0080] In another embodiment shown in Figure 3, a first casing material piece is used to form a first compartment, and a second fabric piece forms a second compartment, in a manner similar to that disclosed in the same applicant's International Publication No. 2014 / 166927 brochure, and the said document is incorporated into this application in whole by reference. Thus, in this embodiment, the first casing material piece forms a conventional pocket for inserting a coil spring, and the second fabric piece forms a further second compartment for housing a cushion pad.

[0081] This arrangement ensures that the first fabric piece preferably completely accommodates the coil spring, and that the second fabric piece is placed over the first compartment to partially accommodate the first compartment and is fixed to the first fabric piece.

[0082] The second piece of fabric may be connected to the first compartment by longitudinal connecting lines 35 and / or transverse connecting lines 33a to 33c.

[0083] In this embodiment, the first fabric may be provided with first lateral connection lines 33a, 33b that form an inter-insertion separation distance between coil springs, as is best seen in Figure 4. Furthermore, the second fabric may be provided with narrower second lateral connection lines 33c, such as a narrow single second lateral connection line, between each pair of adjacent cushion pads, thereby positioning the cushion pads close to each other without any large separation distance between them.

[0084] In this embodiment, the second fabric may be connected to the first fabric by extending the connection lines through both the first and second fabrics in the region where the first and second fabrics overlap, via the first transverse connection lines 33a, 33b. In addition to or instead of this, the second fabric may be connected to the first fabric by extending the connection line through both the first and second fabrics in the region where the first and second fabrics overlap, via the second transverse connection line 33c. In addition to or instead of this, a separate connection may be made between the first and second fabrics. Such a separate connection may be located across the first and / or second transverse connection lines or adjacent to the first and / or second transverse connection lines. Alternatively or in addition, it is also possible to connect the second fabric piece to the first fabric piece by a longitudinal connection line 35.

[0085] Preferably, the second fabric is attached to the first fabric only by connection points or connection lines formed by or located on or adjacent to the first and / or second transverse connection lines 33a to 33c, which are formed by or located on the first and / or second transverse connection lines 33a to 33c. This allows the connection of the second fabric piece to be easily incorporated into conventional pocket spring manufacturing processes.

[0086] The aforementioned connecting lines, arranged in the vertical or horizontal direction, preferably consist of surface joints such as adhesive or welding. The connecting lines may be arranged as continuous straight or non-straight lines, or as discontinuous lines with dots or the like arranged along the lines.

[0087] Similar to the above-described embodiment having two material pieces as shown in Figure 3, the embodiment shown in Figure 2, which uses only a single material piece to form a compartment, may also be provided with first lateral connection lines 33a, 33b that form an inter-insertion separation distance between coil springs, for example, by using two parallel, separated first lateral connection lines between each pair of adjacent springs and a narrower second lateral connection line 33c, such as a narrow single second lateral connection line, so that the cushion pads are positioned close to each other, with no separation distance between the cushion pads or only a very small separation distance. Furthermore, the free ends of the single fabric piece may be connected to each other in the overlapping region by the first and / or second lateral connection lines 33a-33c, or in addition to or instead by separate connections, for example by longitudinal connection lines 32, 34.

[0088] A stabilizing sheet 7 may be connected to the strings on the mattress side, opposite the cushion pad. This stabilizing sheet is preferably made of a flexible material and may consist of a fabric such as a nonwoven fabric, and preferably extends across the entire surface of the mattress. The sheet may be connected to the bottom side of the strings by adhesive, welding, etc. This helps the stabilizing sheet stabilize the mattress on the side opposite the cushion pad and maintain the coil springs in an upright, isolated position.

[0089] However, instead, as already discussed, pocket spring mattresses further include a second cushioning pad located below the lower end of each coil spring.

[0090] Figure 6 shows a schematic manufacturing method and apparatus for producing a continuous string of individually pocketed coil springs of the type described above in relation to Figure 2.

[0091] First, a continuous piece of fabric is folded or wrapped to form two plies of fabric that are connected to each other on one side. Alternatively, two separate pieces of fabric plies may be connected to each other on one side. A compressed coil spring is inserted between the plies, as shown in position A. These plies are then connected to each other along the longitudinal connection line 32 at their open ends, thereby surrounding the inserted coil spring. At this position, the coil spring, if inserted in a rotational position, is reoriented to allow it to stretch. One of the plies extends beyond the connection line 32. A cushion pad 5 is then placed over the housed coil spring. This stage is shown in position B. The extended plies are then wrapped around and cover the cushion pad, as shown in position C.

[0092] The wrapped ply may be connected on the other side along the longitudinal connection line 34. However, it is also possible to connect the covering and wrapped ply only by the transverse connection line. This state is shown in Figure D.

[0093] Subsequently, lateral connecting lines 33 are formed, dividing the string into separate pockets, so that each individual unit has two compartments, and each compartment has only one coil spring or only one cushion pad. This state is shown in Figure E. The lateral connecting lines 33 here serve multiple purposes. One or more lateral connecting lines 33a, 33b located at the lower end between the coil springs separate the coil springs from each other, forming separate pocket compartments for the springs and creating the spacing between the springs. Lateral connecting line 33c at the upper end separates the cushion pads from each other, so that they form separate pocket compartments for the cushion pads and allow the cushion pads to be placed close to each other along the length of the string. Furthermore, it is preferable that one or both of the upper or lower lateral connecting lines also connect the material forming the second compartment to the first compartment in the overlapping region.

[0094] The lateral connection lines 33a to 33c may be formed, for example, by welding. For example, a heating element 6a can be used to form the lower lateral connection lines 33a to 33b, and a separate heating element 6b can be used to form the upper lateral connection line 33c. However, instead, a single heating element may be used to form all the lateral connection lines 33a to 33c one after another or simultaneously. The heating element is preferably an ultrasonic heating element that can move toward the string to apply heat and form a weld at the desired position. However, as is well known to those skilled in the art, other methods of forming welds are also feasible.

[0095] Figure 7 shows a schematic manufacturing method and apparatus for producing a continuous string of individually pocketed coil springs of the type described above in relation to Figure 3.

[0096] First, a continuous piece of fabric is folded or wrapped to form two plies of fabric that are connected to each other on one side. Alternatively, two separate pieces of fabric plies may be connected to each other on one side. A compressed coil spring is inserted between the plies. These plies are then connected to each other along a longitudinal connection line 32 at their open ends, thereby surrounding the inserted coil spring. In this position, the coil spring, if inserted in a rotational position, is reoriented to allow it to stretch. This state is schematically shown in Figure 5a.

[0097] Subsequently, a second piece of fabric is placed above the coil spring, and a cushion pad is placed between the housed coil spring and the second piece of fabric. This is also schematically shown in Figure 5a.

[0098] The second piece of fabric is wrapped around the cushion pad and the top of the housed coil spring. Then, lateral connecting lines 33a to 33c are formed, dividing the string into separate pockets, so that each individual pocket unit has two compartments, and each compartment has either one coil spring or one cushion pad. Here, the lateral connecting lines 33a to 33c serve to separate the compartments housing the coil springs from each other, separate the compartments housing the cushion pads from each other, and create an interlocking separation distance between the coil springs, thereby connecting the second material forming the second compartment to the first compartment. This is schematically shown in Figure 5b.

[0099] As in the previous example, the lateral connection line 33 may be formed, for example, by welding. For example, one or more heating elements can be used, such as ultrasonic welding equipment, which can be moved toward the string and apply heat to form a weld at the desired position. However, as is well known to those skilled in the art, other methods of forming a weld are also feasible.

[0100] The lower lateral connecting lines 33a to 33b generally preferably extend from the lower surface of the spring string to the upper lower surface of the spring string, and preferably extend for a length at least approximately corresponding to the height of the spring. However, the extending length may be further restricted. The upper lateral connecting line 33c generally preferably extends from the upper surface of the spring string to the lower surface of the spring string, and preferably extend for a length at least approximately corresponding to the height of the cushion pad. However, the extending length may be more restricted, or conversely, it may be longer, for example, extending into the region between the coil springs, and possibly even extending across the entire height of the string.

[0101] As schematically shown in Figure 10, the first and second pieces of fabric may be supplied continuously and simultaneously. Thus, the first piece of fabric may be supplied from a first roll 61 of the material, and the second piece of fabric may be supplied from a second roll 62 of the material. These pieces of fabric are then guided into a manufacturing apparatus 63, where the material is formed into pockets, each having two compartments, in the manner described above. Cushion pads are preferably supplied between sheets of fabric. For example, pre-cut cushion pads may be provided in a cushion pad supply source 64, such as a magazine or other form of supply source, and distributed between two sheets of fabric by a dispenser 65 or the like. Alternatively, the cushion pads may be provided as a continuous string that is cut to the appropriate length immediately before distribution.

[0102] This configuration allows for the correct positioning of the cushion pad in a very convenient and efficient manner. The cushion pad is moved together with the fabric sheet throughout the manufacturing process and is held in the correct position by the friction of the sheet.

[0103] Therefore, in both of the aforementioned methods, conventional manufacturing processes can be used to form the pocket mattress, and separate compartments can be easily added to the top of each pocket unit to accommodate cushion pads. This makes the present invention very useful for automated, cost-effective manufacturing, and it is also relatively easy to incorporate the further step of providing separate compartments for cushion pads and inserting such cushion pads into the compartments using already known, well-established manufacturing processes.

[0104] In particular, the order of the previously defined method steps may differ. For example, the spring housing and cushion pad housing may be performed in any order in an automated manufacturing procedure, or they may be performed simultaneously. Furthermore, the connection lines may be provided in any order, or they may be provided simultaneously.

[0105] To form a pocket spring mattress for use in bedding or sheet products, comprising multiple parallel strings of individually pocketed coil springs, the strings formed as described above may be connected to one another by aligning them and, for example, bringing surface adhesion between adjacent surfaces. Such strings can be connected using, for example, adhesive, Velcro, ultrasonic welding, clamps, etc.

[0106] The surface attachments are preferably positioned at the centers of each coil spring where the springs of adjacent strings are closest to each other. The surface attachments may be made as a continuous line extending across the entire string height or across a portion of the string height. Alternatively, the surface attachments may be formed at separate locations, such as connection spots. Such embodiments are shown in Figures 4 and 5, where connection spot 34a is formed at the top of the string, connection spot 34b is formed in the middle of the string, and connection spot 34c is formed at the bottom of the string. However, more or fewer connection spots may be used. For example, it is possible to use only connection spots 34b and 34c, only connection spot 34b, only connection spot 34c, and so on.

[0107] Preferably, there are no connections between adjacent strings at the top of the strings, thereby leaving the area for housing the cushion pad unconnected, and, in some cases, the area for housing the top of the coil springs also unconnected. This improves the individual elasticity of the pocket units and enhances the comfort of the mattress.

[0108] As in the illustrative examples in Figures 4 and 5, surface attachments connecting the strings to each other may be made between all pairs of adjacent coil springs. However, fewer connections may be used, such as bringing surface attachments to only every two or every three pocket units along the length of the string.

[0109] In the embodiments discussed so far, the strings are arranged so that the pockets of different strings are aligned with each other, and as a result, the pockets of different strings contact each other at their outermost surfaces furthest from the longitudinal centerline of each string. However, instead, the strings can be arranged in a staggered configuration, as schematically shown in Figure 11. Preferably, the strings are staggered by a distance corresponding to half the length of the pocket. This increases the contact area between the strings, making the connection between the strings stronger. This arrangement also allows for a firmer and denser mattress. In such an arrangement, the width of the cushion pad can be somewhat smaller than in the embodiments described above, while the length of the cushion pad remains the same.

[0110] Since the cushion pad maintains the stability of the mattress, generally no further structure is required to enhance stability. However, the assembly of parallel strings of springs may optionally be joined to upper and / or lower substantially rectangular boundary wires located on the upper and lower surfaces of bedding or sheet products such as steel frames. In particular, such frames may be used on the side of the mattress where the cushion pad is absent.

[0111] Furthermore, due to the smooth surface provided by the cushion pad, generally no further cover or upholstery is required. However, optionally, a cover pad may be placed over the spring assembly, and / or an upholstered cover may be placed over the pocket spring mattress.

[0112] The mattress may be housed within a cover, for example, made from a woven material.

[0113] Each string of springs preferably comprises a transverse row of individual coil springs, a strip of fabric surrounding the coil springs, and a plurality of cushion pads positioned on the outside of the fabric that houses the coil springs and above the coil springs. The strip of fabric in each string is divided into a plurality of pockets by spaced transverse attachment lines. Each pocket contains one coil spring, and further compartments above each coil spring house at least one cushion pad located above the coil spring. The casing material is preferably formed from a weldable woven material.

[0114] In another embodiment, as shown in Figure 12, one or more additional cushion pads may be located below the coil spring in a further compartment, which is formed and connected in the same manner as the upper compartment.

[0115] The mattress may further comprise a foam material, for example, made of polyether, which is arranged on one or more of the long and short sides of the mattress. The foam material is preferably cut into rectangular blocks and attached to the sides of the strings. In particular, it is preferable to add foam blocks to one or both of the long sides of the mattress. The foam blocks may be, for example, similar in size to the strings, so that during mattress assembly, the foam blocks can be attached to the sides of the outermost strings in the same process as the strings are attached to each other. This eliminates the need for further manufacturing steps or processes and no longer requires the mattress to be placed in a conventional polyether box or the like.

[0116] Mattresses can be used for many different purposes, such as beds, large sofas, and other types of furniture intended for sleeping, resting, and sitting. Mattresses are particularly well-suited for use in vehicles, such as berths in trucks.

[0117] As those skilled in the art will see, the present invention is by no means limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, multiple cushion pads may be arranged within each coil spring unit, each individually pocketed. Furthermore, the separation distance between coil springs may be varied between mattresses, and may also be varied within a single mattress to provide areas with different characteristics within the mattress. For example, a larger separation distance may be used in areas that are hardly exposed to load during normal use of the mattress, and a smaller separation distance may be used in areas exposed to heavier loads. Furthermore, the separate compartments of the unit may be formed in various ways, for example, by a single piece of fabric or by two or more separate pieces of fabric. Such and other modifications of the pocket unit and the mattress formed by such unit constitute part of the present invention, as defined in the appended claims.

Claims

1. 1. A pocket spring mattress for use in a bedding or sheeting product comprising a plurality of interconnected coil springs housed within a continuous cover forming a string of pockets to receive said coil springs, the coil springs in each string are separated by lateral connecting lines; A plurality of such strings are arranged parallel to one another and connected to one another; Adjacent coil springs in each string are spaced apart by an interleaving separation distance; the separation distance is at least 20 percent greater than the diameter of the largest helical turn of the adjacent coil springs; Each of the coil springs has an upper end and a lower end, the pocket spring mattress further comprising a cushion pad positioned above the upper end of each coil spring; The cover is a first compartment that houses the coil spring; a second compartment for receiving the cushion pad; the first and second compartments are separated from each other; Each of the cushion pads has an extension length in a length direction of the string that exceeds a diameter of a maximum spiral winding portion among the spiral winding portions of the corresponding coil spring, the cushion pad is centrally disposed on each of the corresponding coil springs; each of the cushion pads extends on both sides from a corresponding coil spring with the same length in both the length direction of the string and the width direction of the string; A pocket spring mattress, wherein the length direction of the strings and the width direction of the strings correspond to the length direction of the pocket spring mattress and the width direction of the strings, respectively.

2. 2. The pocket spring mattress of claim 1, wherein the separation distance is greater than 25 percent of the diameter of the largest helical turn of the adjacent springs.

3. 3. The pocket spring mattress of claim 1 or 2, wherein the lateral connecting lines have a width along the length of the strings that defines the separation distance.

4. Two lateral connection lines are provided between adjacent coil springs, 3. The pocket spring mattress of claim 1 or 2, wherein the lateral connecting lines are spaced apart along the length of the string to define the separation distance.

5. The cover is a first piece of fabric defining the first compartment; 5. The pocket spring mattress of claim 1, further comprising a second piece of fabric forming the second compartment.

6. the first piece of fabric completely contains the coil spring; 6. The pocket spring mattress of claim 5, wherein the second piece of fabric is positioned to partially contain the first compartment and is secured to the first piece of fabric.

7. the second piece of fabric is secured to the first piece of fabric along at least one lateral connection line extending parallel to a longitudinal direction of the coil spring; The pocket spring mattress of claim 6 , wherein the lateral connection lines comprise surface joints.

8. 8. The pocket spring mattress of claim 1, wherein the cushion pad has a longitudinal extension that exceeds the diameter of the largest of the spiral turns of the coil spring by at least 15%.

9. 9. The pocket spring mattress of claim 1, wherein each cushion pad comprises at least one piece of foam.

10. the cushion pad has an extending width in a width direction of the string, The extension width is smaller than the extension length, 10. A pocket spring mattress as claimed in any one of the preceding claims, wherein the extension width is preferably approximately equal to the diameter of the largest one of the spiral turns of the coil spring.

11. 11. The pocket spring mattress of claim 10, wherein the cushion pad has a generally rectangular configuration with chamfered or rounded corners.

12. 12. The pocket spring mattress of claim 1, wherein the cushion pad comprises a layered construction comprising two or more different materials arranged in a configuration such that a flexible foam piece is secured to a rigid foam piece.

13. 13. The pocket spring mattress of claim 1, further comprising a stabilising sheet connected to the strings at an opposite end of the cushion pad.

14. the parallel strings are arranged side by side and interconnected by surface attachment between abutting surfaces; 14. The pocket spring mattress of claim 1, wherein the surface attachment interconnecting the strings comprises at least one of gluing and welding.

15. 1. A method of manufacturing a spring mattress of the kind comprising a plurality of interconnected coil springs housed within a continuous cover forming a string of pockets for receiving said coil springs, comprising the steps of: encasing the spring within a continuous cover material; forming pockets in the continuous cover material by providing lateral connection lines between adjacent coil springs; interconnecting several strings with each other; Including, Adjacent coil springs in each string are spaced apart by an interleaving separation distance; the separation distance is greater than at least 25 percent of the diameter of the largest helical turn of the adjacent coil springs; Each of the coil springs has an upper end and a lower end, providing a cushion pad above the upper end of each coil spring; The cover is a first compartment that houses the coil spring; a second compartment for receiving the cushion pad; the first and second compartments are separated from each other; the cushion pad has an extension length in a length direction of the string that exceeds a diameter of a maximum spiral winding portion among the spiral winding portions of the coil spring, the cushion pad is centrally disposed on each of the corresponding coil springs; each of the cushion pads extends on both sides from a corresponding coil spring with the same length in both the length direction of the string and the width direction of the string; The method of claim 1, wherein the length direction of the strings and the width direction of the strings correspond to the length direction of the pocket spring mattress and the width direction of the strings, respectively.

Images