FR3127682A1 - Pocket spring mattress and method of manufacture - Google Patents

Abstract

Method of manufacturing a pocket spring mattress, comprising compressing a layer of pocket springs (100) in the two dimensions of the layer, placing a sheet of nonwoven (200) on one side of the tablecloth, and an outer finish of the mattress. The nonwoven sheet (200) is put in place while the web is held in compression (P1, P2) in both dimensions of the web, and by gluing on the periphery (110, 120, 130) of the tablecloth. Picture: 4

Description

Pocket spring mattress and method of manufacture

The invention is in the field of bedding, and more specifically in the field of pocket spring mattresses and their manufacture.

Pocket spring mattresses are based on a suspension structure consisting of a sheet of pocket springs, this structure being able to be surrounded by one or two sheets of non-woven fabric and one or two padding plates of flexible or semi-flexible material. -rigid comprising for example a shape memory material and wadding. The non-woven, when used, is generally used as a stitching structure for the stitches which are then practiced from the outer envelope in thick fabrics or ticking which finally encloses the assembly.

The layers of pocket springs are themselves made up of springs of preferably cylindrical or helical shape, each wrapped in an individual non-woven bag and being organized in rows within which the successive bags are welded, for example by ultrasonic welding. . The rows are further fixed to each other, for example by gluing, so as to form a network of springs arranged in rows and columns at right angles.

This suspension of springs is advantageously, early in the mattress assembly process, put in transverse tension by compression in its two lateral dimensions, then kept in tension. Indeed, this tensioning makes it possible to ensure that the springs better resist the pressures they undergo during the life of the mattress, and consequently wear out less quickly, and also wear out the spring bags less. In the end, the mattress is more durable, because the springs do not sag.

Two techniques aimed at this tensioning and maintaining are known.

First of all, among the pocket spring mattresses, there are streamlined mattresses, for which the edges of the layer of pocket springs are surrounded by rectangular parallelepipeds of foam forming a border, for example polyurethane foam, which, the whole being threaded into the ticking envelope, maintains the lateral and longitudinal compression of the ply.

The foam border also ensures a stable edge finish, to the satisfaction of the user who uses the mattress alternately by lying on it and sitting on the edge.

The nonwovens of the two sides of the sheet of streamlined springs are glued to them by hot-melt glue deposited in the form of a rain of droplets, following the technique of depositing the glue by fiberization. The glue is deposited in an essentially uniform manner on the face of the foam parallelepipeds of the fairing which forms the continuity of the face of the bags as they approach the edges of the ply.

There are also framed pocket spring mattresses, for which a metal frame is placed on the perimeter of each side of the sheet of springs and stapled to the external springs. Here too, this measure ensures the maintenance of the lateral and longitudinal compression of the ply, and therefore the tensioning of the suspension. The frame also ensures a stable finish around the edges, for the satisfaction of the user lying down or sitting down. The fleece is stapled together with the frame to the external springs.

Nevertheless, attempts are being made to reduce the quantity of metal and the quantity of foam used to manufacture the mattresses, and it is therefore necessary to develop new manufacturing solutions that are less costly in terms of materials, or use less materials with a contested ecological balance.

It is proposed in this context a method of manufacturing a pocket spring mattress, comprising a compression of a layer of pocket springs in the two dimensions of the layer, a positioning of a sheet of nonwoven on a face of the sheet, and an outer finish of the mattress, the sheet of pocket springs forming the core of the mattress. The outer finish of the mattress can be done by stitching on the non-woven sheet.

Thanks to the sheet of springs, we maintain sleeping independence and quality comfort.

Remarkably, the nonwoven sheet is put in place while the web is held in compression in both dimensions of the web and the nonwoven sheet is stretched, and by gluing on the periphery of the layer.

This solution makes it possible to obtain mattresses whose sizing is well controlled during production and constant over time, and whose production consumes little foam and little metal, and whose production costs nevertheless remain under control.

According to advantageous and optional characteristics,

- the gluing can be carried out using an adhesive which is deposited in the form of compact beads of glue on the sachets of the periphery of the sheet, before the installation of the nonwoven sheet, the beads being continuous or interrupted. For simplicity, the cords can be deposited parallel to the nearest sides;

- The gluing on the periphery can be carried out more precisely on the two or three outermost rows or columns of springs from the edge of the layer of springs, for a layer of 25 bags out of 33 bags;

Bonding on the periphery makes it possible to maintain the independence of the coating - the large central zone on which the nonwoven is not glued allowing the nonwoven to slide on the springs.

- Bonding can be carried out while the compression of the web is between 12 and 15%;

- A central part of the sheet can be left, against the surface of said face of the web, mobile without gluing, the compression being maintained until the glue solidifies;

- A piece of semi-rigid material comprising a right angle can be placed along the edge of the web at each of its four corners, in the form of an angle iron surrounding the corner spring, or in the form of a prism or parallelepiped replacing a spring removed at the corner of the sheet; This allows to obtain a good aesthetics of the finished mattress, the corners were not radiated, thanks to the presence of the semi-rigid material including a right angle;

- Said face of the web being a first face and said sheet of nonwoven being a first sheet, the manufacturing process may further comprise placing a second sheet of nonwoven on the second face of the web, while the web is held in compression;

- Compression can be carried out in a frame table;

- The exterior finish may include placing a finishing top on each side of the mattress and a ticking strip on the edge of the mattress, the tops being connected to the ticking strip by a sewn strap.

- The edges of the non-woven sheet can be folded over the side edges of the sheet of pocket springs.

The invention also consists of a pocket spring mattress, comprising a layer of pocket springs compressed in both dimensions of the layer, and a sheet of nonwoven on one face of the layer.

The nonwoven sheet holds the web in compression in both dimensions of the web, by bonding to the web at the periphery of the web.

The invention will be better understood, and other aims, characteristics, details and advantages thereof will appear more clearly in the explanatory description which will follow made with reference to the appended drawings given solely by way of example illustrating several embodiments. of the invention and in which:

There shows a sheet of pocket springs which can be used for the invention.

There shows a preliminary step of a method according to a first embodiment of the invention.

Figures 3 to 7 show subsequent steps of a method according to the invention.

There shows the mattress resulting from the manufacturing process of figures 2 to 7.

There shows a sheet of pocket springs which can be used for a second embodiment of the invention.

Figures 10 to 15 show subsequent steps of a method according to the second embodiment of the invention.

With reference to the , there is shown a sheet of pocket springs, flat and rectangular, referenced 100. Each spring 1 is a helical compression spring, which can be cylindrical or conical, and whose longitudinal axis extends perpendicularly to the plane of the sheet 100 The springs which are of similar dimensions to each other are arranged in rows L1 to Ln and in columns C1 to Cn forming a regular checkerboard at right angles, for example of 33 bags in length by 25 bags in width. It is specified that this arrangement is obtained first of all by forming rows of bags within which the bags are welded by ultrasonic welding, and by gluing the rows to each other on their sides using a hot melt glue .

With reference to the , the tablecloth 100 which was visible in is now compressed in length and width in a frame table TC, which stresses the springs evenly, by regular pressing on the edges of the web 100, over its entire length and over its entire width, as shown by the pressures P1 and P2. The springs 1 being compressed in the plane of the sheet, they oppose an increased resistance in the direction perpendicular to the sheet 100, which reflects their transverse tensioning. A compression of 12 to 15% is put in place at this point. It is measured as the reduction in dimension: if the width or length of the uncompressed sheet is 100, after compression this dimension is reduced to a value between 85 and 88.

The tablecloth 100 has an upper face which is accessible by approaching it from above the framing table TC.

With reference to the , beads of glue are placed on the upper face of the sheet 100, on the most peripheral springs. In the embodiment presented, three beads of glue are put in place, each forming a rectangle whose edges are parallel to the edges of the rectangle formed by the sheet 100, recessed towards the inside thereof. They are referenced 110, 120 and 130, from the outermost to the innermost. They are placed on a center line of the outermost columns and rows of springs, namely the columns C1 and Cn and the rows L1 and Ln, for the bead of glue 110, the columns C2 and Cn-1 and the rows L2 and Ln-1, for the bead of glue 120 and the columns C3 and Cn-2 and the lines L3 and Ln-2, for the bead of glue 130. The glue used is for example a hot-melt glue, which is deposited hot, and which solidifies in about one minute. The cords guarantee gluing independently of the exact hold of the upper surface of each sachet, and a localized application in this form makes it possible to avoid the appearance, with use, of unpleasant noises linked to dry glue on a surface that does not sticking to another surface. Indeed, the deposition of the glue in the form of a bead allows all of the glue deposited to be ultimately in contact with the two surfaces to be glued, namely the upper surface of the sachets and the sheet of nonwoven.

With reference to the , a sheet of nonwoven (also called nonwoven) 200 is placed on the upper face of the sheet 100, which remains at this stage held in compression in the frame table TC, and while the glue of the three cords 110, 120 and 130 is still fluid. In addition, the nonwoven sheet 200 is, on approaching contact with the sheet 100 and bonding, kept taut in its two dimensions, in length and in width, as shown by the arrows representing the forces T1 and T2 . Thus, the nonwoven sheet 200 is glued flat to the sheet of pocket springs, with an active application to ensure that contact is complete for the purpose of bonding, and, once the glue has solidified, which occurs quickly, the nonwoven sheet 200 participates in keeping the web 100 compressed in its two dimensions, length and width.

The fact that only the periphery of the sheet of springs is glued to the nonwoven makes it possible to maintain significant coating independence, since pressing on a given spring does not cause the adjacent springs to be driven.

With reference to the , a second nonwoven sheet 300 is placed on the second face of the ply of pocket springs 100. For this, several methods are possible, one of which consists in removing the ply of pocket springs 100 from the table at frame TC and reinstall it there once turned over so as to reapply the compression before setting up the second sheet of nonwoven 300. Another method consists in setting up on the table to frame TC joints configured to lead the overturning of the sheet of pocket springs 100 whose compression is preserved during the overturning, and a third method consists in opening access to the underside of the sheet of pocket springs 100 in the table to be framed TC and in setting up the second sheet of nonwoven 300 on the underside, thus accessing it from below the sheet of pocket springs.

This second sheet of nonwoven 300 is put in place by gluing in a manner similar to what was done for the first sheet of nonwoven 200. From the solidification of the glue, the two sheets of nonwoven woven 200 and 300 hold the web 100 of pocket springs in compression, and it can leave the frame table TC permanently.

With reference to the , the two sheets of nonwoven 200 and 300 are folded along the edge of the ply of pocket springs 100, and angles of semi-rigid material, such as a synthetic or natural foam, are put in place at the four corners of the sheet of pocket springs 100. These angle irons are referenced 400, 401, 402 and 403. They make it possible to ensure a geometric maintenance of each of the corners of the mattress being formed.

With reference to the , a thick strip fabric 500 of the ticking type is placed on the edge of the layer of pocket springs 100 over the entire length of the sides and around the corners, in particular around the angle iron 400 shown in the figure, as well as around the others angles. The strip fabric 500 also covers the folded edges of the first and second sheets of nonwoven 200 and 300.

On each of the two faces of the arrangement thus composed, a plate 510 or 520 is placed, having an outer face of thick fabric of the ticking type, and with reference to the , a loop 550 is sewn to attach the strip fabric 500 to the outer fabric of the tray 510. A similar loop is sewn to attach the strip fabric 500 to the outer fabric of the tray 520. A quilting is made on each of the trays 510 and 520 .

The assembly thus formed is a 1000 mattress of which, apart from the two 550 loops, only the ticking outside the strip of fabric 500 and the trays 510 and 520 is visible.

Due to the bonding between the sheets of nonwoven which have been presented with reference to the preceding figures and due to the presence of the angles at the four corners, the dimensions of the mattress 1000, in width and in length, are particularly well controlled and constant. from one copy of the product to another.

These dimensions are also maintained over time, and the mattress can be used for many years without changing dimensions.

With reference to the , a second embodiment is presented. There is a layer of pocket springs 101 consisting of rows L1 up to Ln and columns C1 up to Cn. The four pocket springs at the corner positions are eliminated, so that there are no pocket springs at the C1L1 position, at the C1Ln position, at the CnLn position, and at the CnL1 position.

Instead of these four pocket springs which are not present, rectangular prisms or parallelepipeds of semi-rigid material, for example natural or synthetic foam, are put in place, and glued with a cord or points of hot melt glue connecting them to the two neighboring springs, in the column and in the row of springs concerned. These corner rectangular parallelepipeds are numbered 410 to 413 in the figures.

In , the sheet of pocket springs 101 consisting of springs and rectangular corner parallelepipeds 410 to 413 is placed in the frame table TC. Thus the pressures P1 and P2 are exerted in the plane of the sheet of pocket springs 101, and a compression of 12 to 15% is put in place at this stage.

With reference to the , we see the placement of beads of glue 110, 120 and 130 as mentioned in the previous embodiment, with the exception of the fact that the outermost bead, referenced 110, is also placed on the four rectangular corner parallelepipeds 410 to 413. Here again, hot melt glue is preferred.

In , the placement of a nonwoven sheet 200 has been shown in a manner similar to that which had been presented in the first embodiment, with a tension T1 and a tension T2 in the two directions of the sheet 200 perpendicular l to each other.

And in , the placement of the second nonwoven sheet 300 on the second face of the layer of pocket springs 101 has been shown, and once the edges have been turned over to the sides, the prisms or parallelepipeds can optionally be seen at the four corners corner rectangles 410 to 413.

There represents the placement of the trays and the outer ticking around the sheet of pocket springs, to finalize the manufacture of the mattress 1010, in a manner similar to what was presented in the first embodiment.

The 1010 mattress, shown in , has the particularity of comprising very little foam-type material and not comprising any framing metal, and nevertheless having excellent retention of its dimensions in both directions of the sheet of pocket springs, as well as good retention geometry of each of the four corners.

The invention typically applies to a mattress which is filled, between the suspension and the outer ticking, with any kind of material suitable for bedding, or to a mattress without any filling. The invention also applies to composite structures bringing together in the same assembly a bed base and a sheet of pocket springs serving as a suspension for the mattress or the mattress topper (for example structures qualified as “Boxspring with topper”).

The invention has been described with continuous beads of glue shown in Figures 3 and 11. But it could be implemented with interrupted beads of glue thus forming dotted lines of beaded glue.

The invention can be implemented on mattresses having a winter side and a summer side, that is to say two sleeping sides, or on mattresses having a single sleeping side.

Claims (11)

Method of manufacturing a mattress for bedding, comprising compressing (P1, P21) a sheet of pocket springs (100; 101) in the two dimensions of the sheet, placing a sheet of nonwoven (200, 300) on one face of the sheet, and an outer finish of the mattress (1000; 1010), the sheet of pocket springs (100; 101) forming the core of the mattress, characterized in that the positioning of the nonwoven sheet (200, 300) is made while the sheet of pocket springs (100; 101) is maintained in compression (P1, P21) and the nonwoven sheet is stretched, the positioning comprising fixing the nonwoven sheet to the ply by gluing on the periphery (C1-C3, L1-L3, Cn-3-Cn, Ln-3-Ln) of the ply of pocket springs (100; 101). Process for the manufacture of a sleeping pad according to Claim 1, characterized in that the gluing is carried out using an adhesive which is deposited in the form of compact beads of adhesive (110-130) on the sachets of the periphery of the ply of pocket springs (100; 101), before the positioning of the nonwoven sheet (200, 300), the cords being continuous or interrupted. Method of manufacturing a mattress for sleeping according to Claim 1 or Claim 2, characterized in that the gluing on the periphery is more precisely carried out on the two or three outermost rows or columns of springs (C1-C3, L1- L3, Cn-3-Cn, Ln-3-Ln) from the edge of the sheet of pocket springs (100; 101), for a sheet of 25 bags by 33 bags. Method of manufacturing a mattress for sleeping according to one of Claims 1 to 3, characterized in that the gluing is carried out while the compression of the sheet of pocket springs (100; 101) is between 12 and 15%. Method of manufacturing a mattress for bedding according to one of Claims 1 to 4, characterized in that a central part of the nonwoven sheet (200, 300) is left against the surface of the said face of the sheet of pocket springs (100; 101), movable without gluing, the compression being maintained until the glue solidifies. Method of manufacturing a mattress for bedding according to one of Claims 1 to 5, characterized in that parts of semi-rigid material (400-403; 410-413) each comprising a right angle are placed along the section of the sheet of pocket springs (100; 101) at each of its four corners, in the form of an angle iron (400-403) surrounding the corner spring, or in the form of a parallelepiped (410-413) replacing a spring removed at the corner of the tablecloth. Method of manufacturing a mattress for bedding according to one of Claims 1 to 6, characterized in that the said face of the ply of pocket springs (100; 101) being a first face and the said sheet of nonwoven being a first sheet (200, 300), the manufacturing method further comprises placing a second sheet of nonwoven (200, 300) on the second face of the ply of pocket springs (100; 101), while the sheet is held in compression. Method of manufacturing a sleeping pad according to one of Claims 1 to 7, characterized in that the compression is carried out in a framing table (TC). Method of manufacturing a mattress for bedding according to one of Claims 1 to 8, characterized in that the external finish comprises placing a finishing plate (510, 520) on each face of the mattress and a strip of ticking (500) on the edge of the mattress, the finishing plates (510, 520) being connected to the strip of ticking by a sewn cord (550). Method of manufacturing a sleeping pad according to one of Claims 1 to 9, characterized in that the edges of the nonwoven sheet (200, 300) are folded over the lateral edges of the sheet of pocket springs ( 100; 101). Mattress for sleeping, comprising a sheet of pocket springs (100; 101) compressed in both dimensions of the sheet, and a sheet of nonwoven (200, 300) on one face of the sheet, characterized in that the sheet of nonwoven (200, 300) maintains the ply of pocket springs (100; 101) in compression in both dimensions of the ply, by sticking to the ply at the periphery of the ply.