Separated pocket spring mattress with cut through string, and a method and apparatus for production of such mattress

IS 2 327 238 T3

DESCRIPTION

Separate wrapped spring mattress with rows in cross section, method and apparatus for producing the mattress.

Field of the invention

The present invention relates to a spring mattress of the kind in which the springs are included in covers, known as a wrapped spring mattress, and to a method and apparatus for manufacturing such a mattress.

Background of the invention

A common technique for making spring mattresses is known as the wrap technique. According to this technique, the springs are included in envelopes, that is, they are included individually by a covering material. Due to this arrangement, the springs become relatively strong individually, such that each spring can bend independently without affecting the adjacent springs, increasing user comfort, as the load will be more evenly distributed across the surface. that receives the load.

An inherent problem with this type of mattress, however, is that they are much more expensive and more complex to manufacture than many other types of spring mattresses, since their manufacture requires large amounts of material and, in addition, many different stages of joining and assembly. Furthermore, these mattresses are comparatively heavy and compact due to the large amount of material required, which in turn tends to make the mattresses relatively stiff.

Therefore, a need exists for a mattress that is easier and / or less expensive to manufacture, but at the same time offers comfort at least equivalent to that obtained in wrapped spring mattresses of the prior art.

An earlier solution to this problem is described in WO 02/44077 by the same applicant. According to this solution, the springs located adjacent to each other within a row are separated by a distance apart, which makes the mattress less compact and thus cheaper and easier to manufacture. The spacing of the springs is obtained by providing double welds between the springs, the welds are parallel to each other and arranged at a certain distance from each other. Alternatively, the separation is performed by a weld extending in the longitudinal direction of the die. Although this mattress offers a number of advantages compared to the prior art, its manufacture remains relatively complicated and expensive.

On the other hand, a common problem associated with basically all wrapped spring mattresses, including the one described above, is that excess cover material accumulates on the surface and bottom of the rows. This is a natural consequence due to the fact that the covers used are not adapted to the shape of the springs, while the thickness of the springs is such that they stretch the locally formed casing covers. Material build-up on top and / or bottom results in undesirable layers in the mattress, called false fluffs, which have poor pressure bearing capacity and are experienced as uneven and uncomfortable for the user. In addition, the accumulation of the material implies a great loss of material, which of course is ineffective in terms of costs.

Another common problem associated with basically all wrapped spring mattresses is that the mattress is relatively compact, which decreases air circulation through the mattress. This is a disadvantage that the user may perceive the mattress to be unnecessarily hot, in particular against parts of the body that are in direct contact with the mattress. In addition, a continuous air circulation ensures better hygiene of the bed, which maintains the freshness of the bed for a longer period of time. It is true that the increased space between the springs as described above with reference to WO 02/44077 increases the aeration of the mattress, but there is also in this mattress a need for an increased circulation of air. On the other hand, a problem with this type of mattress is that the residual ends of material are formed at the end of the rows, which in addition to being a disadvantage in terms of cost also makes the mattress asymmetrical and shapeless.

A similar type of rows for use in mattresses are disclosed in DE 202 15 963, where pairs of the seams between the shells form a gap between the springs. Additionally, slits with an open end may be provided facing one or both of the ends of the rows, with the intention of increasing the individual strength of the springs.

It is known from US 1,455,847 to provide grooves between adjacent rows within the same row. However, this mattress is of another type to that described above, in which the rows are interconnected in a different way. Today, the conventional way to interconnect rows to form wrapped mattresses is to interconnect them by gluing them between the contact surfaces. In the mattress described in US 1,455,847, the rows are instead interconnected by threading a tie strip through the row slots according to different patterns, this is the only purpose for which the slots are provided. In addition, the documents

IS 2 327 238 T3

5,319,815 and DE 40 26 502, for example, describe mattresses in which the cuts are provided in the rows. In these mattresses, the cuts are provided from the bottom or surface of the rows. Also, the rows in these mattresses are not arranged in parallel to each other, but transversely cuts are convenient for coupling the cross-laid rows together. DE 44 35 771 describes a mattress in which the rows are provided with cuts in the center of the row. Also in this case, however, the mattresses referred to have crossed-laid rows, and the purpose of the cuts is to allow the rows to be threaded through other rows.

Object of the invention

One of the objects of the present invention therefore is to provide a spring mattress of the class defined in the introduction, and a method and apparatus for the manufacture of the mattress, by means of which the disadvantages referred to above are completely or at least partially eliminated.

This object is achieved in a spring mattress and by means of a method and apparatus for manufacturing the mattress in the manner defined in the appended claims.

Brief description of the invention

According to one aspect of the invention, there is provided a longitudinal row spring mattress comprising a plurality of interconnected coil springs enclosed in covers. The mattress comprises a plurality of such parallel rows, arranged side by side and interconnected by surface bonding, such as gluing or welding, between the contact surfaces. Furthermore, a slit is provided between at least two springs positioned adjacent to each other within the same row, wherein the slit allows an increased spacing distance (SA) to be formed between adjacent springs. Preferably, the slit is provided such that you are completely included between the top and bottom of the row, that is, the slit begins and ends at a distance from the top and bottom edges, respectively, of the row.

Surface bonding herein means all means and methods of bonding two surfaces, such as gluing, welding, welding or the like.

The gap thus provided between the adjacent springs allows the springs to be separated from each other causing the gap to open. The material remaining in the row still holds the row together, while the excess material is pulled from the top and bottom of the row respectively.

This gives you a number of advantages. Excess material at the top and bottom of the row is stretched, which eliminates the problem of so-called false fluff. Furthermore, much better material savings are achieved in terms of roofing material.

Relative to the prior art mattress described in WO 02/44077, the same advantages are obtained with springs that are spaced apart in the longitudinal direction of the rows. However, a much better material economy is achieved in terms of cover material, and considerably less cover material is required to produce a row of the same length, having the same number of springs and the same gaps. The gaps between some springs make the mattress less compact and therefore fewer springs are required, the operation of including the springs in covers is facilitated and so on. However, the gaps do not significantly affect the comfort of the mattress. In fact, it has even been found that in some cases the increased distance between the springs adds to the individual resistance of the spring, which increases comfort, since each individual spring can carry independently comparative loads.

Due to the efficient use of springs and cover material, the mattress is also relatively inexpensive and easy to manufacture.

On the other hand, the slits, which during the separation open to form holes, which allow the air to circulate transversely through the rows. Since the separation of the springs also results in air ducts that are formed transversely from the direction of the mattress, a highly efficient air circulation mattress is completely obtained.

According to a preferred embodiment, the slits are provided between essentially all adjacent springs in essentially all rows placed in parallel. This allows the advantages described above to be obtained in all parts of the mattress.

However, it is equally possible for the grooves to be provided only between some of all the adjacent springs of at least some of the rows to obtain zones with different characteristics through the mattress. In this way, zones of different firmness can be easily provided in the longitudinal direction of the mattress, for example, or different halves of a double-bed mattress can have different properties.

IS 2 327 238 T3

Furthermore, the cover material is advantageously attached together on both sides along the groove to close the covers along the groove. This closing operation can be performed after the slit has been formed, but is preferably performed before the slit is formed. In this case, the gap can be provided between two seam lines running side to side. Alternatively, the slit can be provided in the center of a bond line, particularly if a slightly wider bond line is used. However, in the case of the closing cut, thin bond lines can also be used.

In a preferred embodiment, the springs are spaced apart by a distance that exceeds about 10% of the diameter of the largest of one of the coil turns of the adjacent springs, and preferably exceeds 15%, more preferably 20%. This allows efficient mattress manufacturing, but does not adversely affect mattress comfort. Furthermore, it is preferable that the spacing distance is greater than 1 cm, and that the density of the springs in the row direction, in the rows in which the slits are provided, is less than 15 springs per meter, and preferably less than 13 springs per meter.

According to another aspect of the invention, there is provided a method for manufacturing a spring mattress comprising the steps of arranging the coil springs in such a way that they are included in covers in longitudinal rows, interconnecting a plurality of parallel rows from side to side. side for surface bonding between the contact surfaces, and to provide a gap between at least two springs located adjacent to each other within the same row, where the slit allows an increased spacing distance (SA) to be formed between adjacent springs.

The above steps can be performed in essentially any chosen order, although from a manufacturing point of view it is preferred to first arrange the springs in rows, before joining the roofing material that forms different rows.

The present method produces the advantages that correspond to those described with reference to the first aspect of the invention.

According to a preferred embodiment, the step of providing coil springs in such a way that they are included in covers in longitudinal rows, comprises the partial steps of arranging a strip of cover material so that it bends over the springs arranged in succession. between them provide a longitudinal bond line, such as a weld or glue line, at the open end of the strip thus bent, and fix, before or after providing the longitudinal bond line, at least one transverse bond line between adjacent springs in each pair of springs.

Thus an efficient production is obtained, while at the same time the manufacturing method can be easily combined with previously described production steps. The step of providing grooves between the springs located adjacent to each other within the same row is preferably performed at the same time as, or directly after, the arrangement of at least one transverse bonding line between the springs.

According to a third aspect of the invention, there is provided an apparatus for manufacturing a spring mattress, comprising a means for arranging the coil springs included in covers in longitudinal rows, a means of interconnecting a plurality of parallel rows side by side by the surface bonding between the contact surfaces, and a means for providing a gap between at least two springs located adjacent to each other within the same row, where the slit allows an increased spacing distance (SA) to be formed between adjacent springs.

The present apparatus produces the advantages that correspond to those described above with reference to the first and second aspects of the invention.

Additional features and advantages of the invention will be apparent from the claims and the following description of the preferred embodiments.

IS 2 327 238 T3

Brief description of the figures

In the attached figures:

Figure 1 is a perspective view of a part of a spring mattress designed in accordance with the invention;

Figure 2 is a side view of a row with springs included used in a mattress according to the invention, in a position before separation;

Figure 3 shows the row of Figure 2, but in a position where the row has been separated;

Figure 4 is a flat top view of a part of a mattress according to one embodiment of the invention.

Figure 5 is a perspective view of a piece of an apparatus, according to a first embodiment, for manufacturing a mattress according to the invention;

Figure 6 is a perspective view of a part of an apparatus, according to a second embodiment, for manufacturing a mattress according to the invention;

Figure 7 is a perspective view of a part of an apparatus, according to a third embodiment, for manufacturing a mattress according to the invention;

Figure 8 is a perspective view of a part of an apparatus, according to a fourth embodiment, for manufacturing a mattress according to the invention;

Figure 9 is a flat top view of a mattress comprising different zones according to an embodiment of the invention; Y

Figure 10 is a side view of the mattress in Figure 9.

Detailed description of the preferred modalities

The invention will be described in the following for the purposes of exemplification by means of the embodiments and with reference to the accompanying figures.

A spring mattress according to the invention comprises a plurality of interconnected coil springs 1, which are included in covers 2, as shown in Figures 1-4. Suitably, the cover is made of a preferably weldable textile fabric except other materials, such as various types of plastic material, could also be used. It is also possible to use non-weldable textile fabrics, such as cotton fabrics. Normally, the 3 rows of interconnected included covered coil springs are manufactured automatically, whereby the strips are cut into suitable lengths and joined side by side for mattresses.

Preferably the covers are sized to ensure that the maximum included height equals at least 3 cm and preferably at least 5 cm.

Coil springs of many different sizes could be used in conjunction with the present invention, and in principle any desired spring size, large or small, can be used. Preferably, however, springs having a diameter of 2-10 cm are used, and more preferably a diameter of about 6 cm. Preferably, the springs comprise at least four spiral turns and preferably less than 10 spiral turns. Furthermore, it is an advantage to manufacture the helical coil wire springs having a thickness in the range of 0.5 to 3.0mm and preferably a wire thickness in the range of 1.5 to 2.2mm.

In the spring mattress according to the invention a slot 4 is provided between at least two adjacent springs of at least one row. Preferably, the slit is provided in such a way that it is completely enclosed between the surface and the bottom of the row, this is made by the slit that starts at a distance below the top of the row and ends at a distance above the row bottom. This means that the row remains unbreakable at the top and at the bottom even after the indentation has formed. The slit allows the springs to be spaced, from the non-spaced position shown in Figure 2 to the spaced position shown in Figure 3, where an increased spacing interposing distance SA is formed between these adjacent springs. This will cause the slit to open, while the remaining row material interconnection at the top and bottom will be stretched.

Preferably, this type of gap is provided between essentially all adjacent springs in the row, and in essentially all rows arranged in parallel with each other.

The interposed spacing distance SA thus obtained preferably exceeds 10% of the diameter of the largest of one of the spiral turns of the adjacent springs, and preferably exceeds 15%, and more preferably

ES 2 327 238 T3 exceeds 20%. Furthermore, the separation distance preferably exceeds 1 cm. These spacing distances are preferably arranged between essentially all springs in the longitudinal direction of the mattress.

Furthermore, it is advantageous for the cover material to be joined on both sides along the groove to close the covers along the groove. This improves the ability of the covers to support the opening and eliminates the risk of the springs releasing from the casings during use. This can be done by providing the rows with two joining lines 5, such as solder joints or glue lines, to join the covering material on both sides of the slit 4. The joining lines can both be provided before or after providing the cleft.

Instead of several bond lines it is, however, also possible to have only one bond line, where the slit is provided exactly in the center thereof so that the bond line still carries the covering material together in both. sides of the slit.

The seam lines, comprising for example weld or glue lines, as described above, can be provided as continuous lines or as different size spot weld seams placed along the lines. Other types of joints are also possible, for example one or more stitched seams.

The invention makes it possible to use less than 30 springs and preferably about 25 springs and more preferably about 22 springs in mattresses having a length of more than 180 cm. It is also preferable that, in mattresses according to the invention, the density of springs in the longitudinal direction or directions, in which the spacing distances are provided, is less than 15 springs per meter and preferably less than 13 springs per meter. .

Furthermore, in the mattress according to the invention several rows are arranged in parallel, and interconnected side by side by surface bonding joints 6 of the contact surfaces. The surface bonding can be done by gluing, welding or the like.

In the manufacture of mattresses in accordance with the above, the following stages are performed in any chosen order:

or arrange the coil springs (1) in such a way that they are enclosed in covers (2) in longitudinal rows of covering material. This stage alternately preferably comprises the partial stages of □ fixing a strip of a covering material so as to bend over the springs arranged in succession between them, □ providing a longitudinal weld 7 or glue line at the open end of the strip thus dubbed,^Y □ fix, before or after the arrangement of the longitudinal weld / glue line 7, at least one transverse weld 5 or glue line between the adjacent springs 1 in each pair of springs;

or interconnecting a plurality of parallel rows side by side by surface bonding between the contact surfaces; This stage is preferably carried out by gluing and / or welding;

or by providing indentations between at least two adjacent rows within the same row, and pulling the row out to separate the springs.

Preferably, the step of providing the indentations is performed at the same time as, or directly after, the arrangement of at least one transverse glue / weld line between the springs.

As already mentioned, the covers comprising the springs are preferably arranged in successive rows, whereby such rows are joined together side by side by the surface joint as indicated in figure 4. Preferably, the rows are joined together at vertically spaced attachment points 2-3 opposite the associated spring. A larger or smaller number of attachment points could of course also be used. It is also possible to use one long bond line that runs essentially parallel to the longitudinal direction of the springs instead of several shorter bond points. It is also possible to join the rows by means of a row of glue or the like extending in the direction of the extension of the strips. The interconnection of rows side by side in succession may be accomplished by welding or gluing, as previously mentioned. However, this interconnection can be accomplished using alternative forms of surface bonding, such as clamps, Velcro tapes, or some other convenient bonding method.

By joining the rows in this opposite way to the springs in the respective row, the spacing distances will be placed in alignment with each other, as indicated in the embodiment shown in figure 4. This position is a preferred one, although it is equally possible to arrange the rows in such a way that the springs are positioned offset relative to each other. In the latter case, the springs in their entirety can, if desired, be arranged more thickly through the mattress than is the case in conventional wrapped spring mattresses.

IS 2 327 238 T3

It is also possible to use different separation distances in different zones or areas of the mattress and to use, for example, larger separation distances in areas that in normal use of the mattress are less exposed to the load, and smaller separation distances in areas exposed to loads. heavier. This can be controlled by determining between which spring grooves are provided, how long the grooves are, where in the rows the grooves are provided, how the rows are joined, etc.

An example of a mattress comprising different zones is shown in Figures 9 and 10. In this example, the mattress comprises several different zones in the longitudinal direction thereof. In a first zone I located at the leading end of the mattress, the rows are cut through between the springs, in the manner described in detail above. In normal use, this area is loaded by the user's upper body, starting from the waist up. In a second zone II, the rows are not cut through. This area corresponds to the curve of the user's back. After this, a short zone III is provided in which the rows are cut transversely. This area corresponds to the buttocks of the user. Then another zone IV is provided in which the rows are not cut transversely, where the zone corresponds to the thighs of the user. Finally, the foot end of the bed comprises a large area, cut transversely V, which corresponds to the legs of the user from the thighs downwards. This bed offers support for the user's back and thighs, while allowing the other part of the body to sink deep into a soft mattress. In this way, a more comfortable mattress is obtained, in which the loads on all parts of the body are distributed more evenly.

However, many other variants of the zone division are conceivable. It is possible, for example, to divide the mattress into a greater or lesser number of zones in the longitudinal direction of the mattress. An example is to use only three zones. Furthermore, it is possible to divide the mattress into zones also in the latitudinal direction, interconnecting rows with non-identical cuts between the springs. In this connection, the springs can also comprise different numbers of springs. This allows, for example, to obtain a mattress that is softer in the middle (with cut-through rows) and hard towards the edges (with fewer cut-through rows). On the other hand, when manufacturing double beds, for example, inhomogeneous rows can be used on different mattress halves, thus to better adapt the mattress for the use of two people with different needs and desires.

It is, of course, possible to obtain corresponding zone divisions by using mattresses which are instead formed from transverse rows and not from longitudinal rows described above.

An apparatus for manufacturing a spring mattress as described above and for carrying out the method listed above may comprise:

* means for fixing coil springs 1 included in covers 2 in longitudinal rows 3 of a cover material. Mediums of this kind are previously known within the field and have previously been used to manufacture wrapped spring mattresses.

* means for interconnecting a plurality of parallel rows side by side by surface bonding between contact surfaces. Medium of this kind is also previously well known within the field and has previously been used to manufacture wrapped spring mattresses, * means for providing a gap between at least two springs located adjacent to each other within the same row, where the gap allows an increased spacing distance (SA) to form between adjacent springs. Medium of this kind has not been previously used in this type of apparatus and will be described in greater detail later.

The means for fixing coil springs in such a way that they are included in covers, advantageously comprises means for fixing a strip of a cover material 2 so as to bend over the springs 1 arranged in succession between them, the means for fixing a line joint 7, such as a solder or glue line, at the open end of the so bent strip, and the means for fixing at least one transverse joint line 5, such as a line of solder or glue, between adjacent pairs of springs in the rows.

The means for fixing indentations may consist of a cutting tool 10 arranged to move towards the covering material, as shown in figure 5. In this case, the cutting tool consists of a rotary cutting tool, comprising an edge circular shear, which can be rotated during operation. Furthermore, the cutting tool can be movable in a direction towards and away from a work table in which the cover material 2 is placed during use, as indicated by the arrow R1. Preferably, the cutting tool is arranged directly adjacent to the means to fix the transverse bond lines 5. The means may consist, for example, of the welding equipment 20 for ultrasonic welding, with two welding elements 21. The welding equipment is preferably movable in the same way as the cutting tool, but independently of it, as indicated by the arrow R2. This allows the welding equipment to be lowered towards the cover material to create two parallel spot weld lines 5, and the cutting tool will be lowered towards the cover material to create a gap 4 between it, while at the same time the material cover travels relative to welding equipment and cutting tool, as indicated by arrow R3. However, it is instead equally possible to cause the welding equipment 20 and the cutting tool 10 to move in the direction R3 and the covering material to remain stationary.

IS 2 327 238 T3

In this embodiment, first the tool of the welding equipment stamps the covering material, and only after this is the slit formed by the cutting tool. The opposite approach is also possible, ie the groove is formed first, and only after this are the welds provided along the edges of the groove sides.

As an alternative to the embodiment described above with reference to Figure 5, a welding equipment 20 'comprising only one welding element can be used, as shown in Figure 6. As a result of the same, only one line is formed. junction 5, which is separated by slit 4. In this case, it is an advantage to provide a slightly wider line of junction, to ensure that a satisfactory interconnection is obtained on both sides of the slit. In other respects, the same arguments as applied above with respect to the use of the equipment and the interrelationship between the welding equipment, cutting tool and casing material.

Instead of a rotating cutting tool, as described above with reference to Figures 5 and 6, a non-rotating tool 10 can be used, as shown in Figure 7. This tool is movable towards and away from the material of covered in the manner described above. The non-rotating tool may have a flat cutting edge 11 ', as shown in Figure 7, but other designs are also conceivable. For example, the cutting edge can be concave, convex, serrated, grooved, or the like. On the other hand, the cutting edge may be arranged parallel to the roofing material, as shown in Figure 7, or more or less inclined relative to the plane. The cutting tool can also be fixed before or after the welding equipment. In the case where multiple welding elements are used it is, however, also possible to arrange the cutting tool at the same level as the welding elements and between them, as shown in figure 7. This allows a very compact design of the apparatus. .

In addition, it is possible to arrange the cutting tool 10 and the joining tool 20 'on opposite sides of the covering material, as shown in the working example in figure 8. More space is thus available for each tool and therefore consequently, their manufacture and use is simplified.

As described above, it is possible to use joining tools, such as the welding means, which is movable along a line and thus activated continuously or intermittently to form the joining line. However, it is also conceivable to use the joining tools 20 'whose extension in the longitudinal direction corresponds to that of the joining line. An example of such a tool is schematically shown in Figure 8. In such an embodiment, the bonding tool does not have to travel along the bond line, but only up and down to "stamp" the bond line between the springs. This operation can be carried out considerably more quickly, thus allowing the speed of production to be increased.

Slit-adapted apparatus according to the above description can be integrated with most prior art manufacturing equipment for the manufacture of wrapped spring mattresses. It is also conceivable, however, to arrange the cutting tool separately from the rest of the manufacturing equipment. Thus, the welding equipment can be located before the cutting equipment in the direction of the course of the swaths, where the detection means can be used to detect the joint lines before the cutting operation. Different types of detection means are conceivable, such as the mechanical means that detects the position of the springs on both sides of the weld seam, the optical means that identifies the weld seam in the material, etc.

The mattress according to the invention offers resistance properties equivalent to those achieved in conventional wrapped spring mattresses, providing the same firmness, comfort and so on. Springs possibly somewhat harder than normal can be used to increase the firmness of the mattress. Alternatively, the same effect can be realized, however, in other ways, for example by means of springs which are included are subjected to a higher preload tension.