Procedure for manufacturing a mattress cover with a padded outer layer and a gusset, and a mattress cover thus manufactured

The present invention relates to a procedure for manufacturing a mattress cover with a padded outer layer and a gusset, and a mattress cover manufactured thereby.

In the mattresses of known type, the mattress panels are attached to the side bands by means of a seam that is concealed by a fabric edging tape that simultaneously joins and covers the join between the two component parts: this solution determines a tension on the surface of the mattress panels.

With reference to figures 1-4, in order to overcome this drawback, use is known of a procedure, as described in the Italian patent No. 1295277, according to which the side band 2 is joined to the mattress panel 1 not directly, but by means of a gusset 4 (fig. 1), which can open outwards and thereby transfer the tension due to the stitching 3 of the tape to the area underneath the mattress panel.

This manufacturing solution demands a series of time-consuming procedures that have to be implemented by suitably-trained personnel.

These steps include first preparing the gusset 4, the fabric 5 of which has to be coupled with a padding material 6 (generally similar to the material comprising the side band 2), folded in two parts 7 and 8, with a seam 9 stitched along the fold (figures 2.1, 2.2, 2.3).

The resulting gusset is then measured and cut into four portions A, B, C, D, two of which C, D, correspond approximately to the lengthwise dimensions of the mattress, and two A, B, correspond approximately to the width of the mattress (fig. 3).

The ends of each portion must be cut to form a 45° angle so that, when placed at a 90° angle with respect to another portion, at their point of contact E, they can be matched with the other portions without leaving any excess material: the joins between the four portions of gusset coincide with the corners of the mattress. In practical terms, the joining of the four portions of gusset gives rise to a frame that has the same dimensions as the mattress.

In the next step, the upper part 10 of the gusset 4 is attached to the mattress panel, then the lower part 11 of the gusset 4 is attached to the side band 2 by means of a seam 3, concealed with edging tape, all around the perimeter (fig. 1).

Then it becomes necessary to join the inside of the gusset 9 to the mattress panel 1, because otherwise, when in use, the mattress would tend to "swell" with an "accordion" or "bellows" effect. In fact, the gusset attached to the side band would open out and return almost to its original extension (before it was folded and stitched 7, 8, 9).

The process for joining the gusset to the mattress panel demands the use of a special sewing machine fitted with a curved (instead of a straight) needle as there is no alternative method for joining the two materials because the thickness of the padding on the mattress panel would prevent the use of a conventional sewing machine. Moreover, given the difficulty of passing through the full thickness of the padding on the mattress panel combined with the thickness of the gusset, this stitching would prove particularly troublesome and slow to complete because any imperfections in the seam would carry the risk of reducing the life of the product and/or giving rise to an aesthetically unacceptable result.

In addition to being extremely laborious, this known method for manufacturing mattresses with a gusset and a padded surface layer on the mattress panel calls for highly-skilled workers and carries the risk of reducing the life of the mattress. It also has another drawback in common with traditional mattresses, in that the mattress panels are never perfectly flat; instead, where they are joined 12 to the side band, they become a few centimetres lower because of the tension generated at the interface between the side band and the mattress panels: see figure 4, showing the difference 13 between the height at the centre 11 and at the edge 12 of the mattress.

This imperfect planarity of the mattress panels poses the problem that the mattress cannot be used near the edges to avoid the user having the impression of sliding towards the outer edge of the mattress.

Thus, the object of the present invention is a procedure for manufacturing a mattress cover with a padded surface layer and a gusset, and a mattress cover manufactured thereby, with a view to overcoming the above-described problems.

The object of the present invention is therefore a procedure for manufacturing a mattress cover, said cover comprising at least one mattress panel, a side band, and at least one gusset inserted between said mattress panel(s) and sideband, characterised in that it comprises the following steps:

• preparing said gusset folded lengthwise into two parts and placing it ready-folded on the edge of the mattress panel on the inside of the mattress cover;
• stitching said folded gusset directly onto said mattress panel, along a first seam inwardly recessed from the edge of the mattress panel, in correspondence with said stitched fold that divides the gusset into two parts.

Another object of the present invention is a device for implementing the procedure, characterised in that it comprises:

• a sewing machine;
• guiding and folding means suitable for cooperating with said sewing machine, and for folding said gusset lengthwise in two parts and placing it ready-folded along the edge of the mattress panel internal to the mattress cover, to enable the stitching of the gusset to said mattress panel along said stitching line inwardly recessed from the edge of said mattress panel, in correspondence with said fold dividing said gusset into two parts.

In particular, the object of the present invention is a procedure and a device for manufacturing a mattress cover with a padded surface layer and a gusset, a mattress cover manufactured thereby, and also a modified sewing machine for implementing the procedure, and a gusset, all as described in more detail in the claims, which form an integral part of the present description.

Further objects and advantages of the present invention will emerge more clearly from the following detailed description of an embodiment of the same (and variants thereof) and from the attached drawings, which are provided merely as a non-limiting example, wherein:

• figures 1 to 4 show steps in the manufacture of a mattress of known type;
• figures 5 and 6 show a mattress manufactured according to the procedure forming the object of the present invention;
• figures 7 and 8 show a sewing machine modified according to the present invention.

The same reference numbers and letters in the figures identify the same elements or component.

The procedure according to the present invention involves concentrating the previously-described steps forming part of the known state of the art into a single step, i.e.

1. 1. folding the gusset;
2. 2. attaching it by means of stitching in its folded position;
3. 3. preparing the gusset frame by cutting the four portion of gusset comprising said frame;
4. 4. shaping the two ends of each portion with a 45° angle;
5. 5. joining the corners of the frame by means of stitching;
6. 6. fixing the inner side of the gusset, shaped in the form of a frame, to the padded mattress panel;
7. 7. repeating all these steps on the other side of the mattress.

This is achieved with the aid of a special sewing machine, described below, the needle of which is particularly sturdy and capable of passing through any layers of padding in the mattress panel (generally combined with the fabric by means of quilting) and emerging on the opposite side in order to simultaneously form a seam that includes the inner, folded side of the gusset. The mattress panel may not necessarily be padded, it may consist of fabric alone.

As shown in fig. 5, the result is a quilted panel 1' with the gusset 14 attached to its underside all around its perimeter by means of a seam 15 for attaching the gusset that is also visible on the upper side, forming a contour in the mattress panel that lies a constant distance away from its edge corresponding to approximately the width of the underlying folded gusset.

This "visible" seam also makes it possible to avoid what was previously unavoidable, i.e. the curvature of the mattress panel. In fact, where this seam is made between the mattress panel and the gusset, the thickness of any padding is reduced to a few millimetres due to the effect of the through stitching.

As shown in figure 6, the parts unaffected by the seam, but located in its immediate vicinity, tend to swell due to the effect of the tension generated by the seam 15. The parts 16 around the edge of the quilted panel, particularly the outermost part 17, all around the perimeter of the mattress can even rise towards the inner part of the panel 1', because they are no longer restricted, thus avoiding the above-described problem of the mattress sloping away at its edges.

The gusset according to the invention can be achieved by coupling the fabric used for lining the mattress (on the outer side) with a backing material (a fabric, nonwoven, PVC, polyurethane or other material suitable for the purpose) of suitable thickness, which may also be considerably less than the one used in the previously-described known procedures.

Alternatively, the gusset according to the invention can be achieved using a different fabric from the one used for lining the mattress, e.g. a heavy fabric, in a single layer, instead of being coupled to a backing material.

The coupling of any backing material can be done using adhesives, heat, ultrasound methods or simply by stitching straight seams along the length of the strip of fabric, or by any other means suitable for keeping the two (or more) materials joined together.

It is not necessary to perform any other steps to prepare the gusset.

With reference to figures 7 and 8, a sewing machine 20, modified according to the present invention, comprises a head 21 fitted with a straight needle 22 that performs a vertical reciprocating movement to stitch seams. The internal components of the machine can be made according to the known state of the art.

The sewing machine 20 comprises guiding means 23 consisting of the following elements:

• an arm 24 hinged at one of its ends 25 to the body of the sewing machine at a certain distance from the needle 22;
• a feeding and folding device 26 placed at the opposite end of the arm 24 in a position facing the needle 22. The device 26 comprises a hollow saddle 27, capable of sliding along a guide 28 attached to the sewing machine's flat bed. A hollow feeding and folding member 29 is connected to the outer end of the saddle 27, with a variable cross-section that starts externally with a curved gore-shaped cross-section 30, and ends with a folded cross-section facing the saddle 27, to which it is connected;
• a pair of parallel cylindrical guide rollers 31, at the outer end 30 of the member 29. This pair of rollers is attached to the arm 24 by means of a bracket 32. The height of the pair of rollers and the distance between them are such as to enable the strip of material used to form the gusset 14, consisting of an open band 14', to slide between them. Said band 14' is carried by the rollers 31 and enters the opening in the outer end 30 of the member 29, emerging folded in two through the slot in the saddle 27 that faces towards the needle 22, thereby forming the gusset 14. The two folded parts may be of the same size, or they may be of different sizes, depending on the shape of the feeding and folding member 29, and especially on the part connected to the saddle 27.

In operation (figure 8), the band 14' is passed between the guide rollers 31 and inserted in the opening 30; then the arm 24 is turned so as to bring the saddle 27 into position opposite and juxtaposing the needle 22. The saddle can be fitted with a recess so that it surrounds the area in which the needle punctures the fabric.

The band 14' is thus fed through the member 29 so that it emerges from the saddle 27 ready folded in two and opposite the needle. Then the quilted panel 1' is positioned underneath the needle, so that the folded gusset 14 comes to lie above it, aligned with its outer edge. The sewing machine 20 is operated, making the needle 22 pass through both the gusset 14 and the panel 1', producing the above-described seam 15 in line with the fold in the gusset as the juxtaposed mattress panel and gusset are progressively fed forward. The seam 15 is sewn at a distance from the edge of the panel 1' that approximately corresponds to the width of the side of the folded gusset in contact with the mattress panel.

The seam can thus be completed even at the rounded edges of the mattress panel 1', which is generally rectangular in shape, simply by turning the panel through 90°, without interrupting or cutting the gusset 14, but simply making it curve around the panel as it proceeds, obtaining a result as shown in the previously-mentioned figure 5.

The subsequent steps involve:

• stitching the edge of the upper side 10 of the gusset to the edge of the panel 1';
• stitching the edge of the underside 11 of the gusset to the edge of the side band 2;
• finishing the edges of both the side band 2 and the panel 1', with a seam concealed with edging tape, for instance, around the perimeter 3.

The sewing machine 20 can be of the type operated entirely manually, or it can be fitted with suitable automatic or semiautomatic, possibly computer-aided controls. Its automatic control can be implemented in any known manner.

There may be variants to the embodiment of the non-limiting example described herein without departing from the scope of the present invention protected by the patent, including all the equivalent embodiments for a person skilled in the art.

The advantages deriving from the application of the present invention are self-explanatory.

The new method for manufacturing a mattress with a padded surface panel is in fact:

• economically advantageous because it eliminates the numerous steps needed to manufacture the product according to the known state of the art;
• it enables the product to be manufactured by less skilled workers;
• it enables a mattress to be manufactured with mattress panels that are perfectly flat or even with a slightly raised edge all around its perimeter;
• it reduces the use of materials because the gusset can be less padded than in the known state of the art.

The gusset is the only element that is modified: both the side bands and the mattress panels remain the same as in a traditional mattress.

From the above description, a person skilled in the art is capable of achieving the object of the invention without introducing any further structural details.