A mattress manufacturing system for assembling mattress layers by stacking them on top of each other

Abstract

The invention relates to a mattress manufacturing system (1) with at least one adhesive unit (4) for enabling the mattress layers (Y) to be adhered together. The novelty of the invention is characterized in that it comprises at least one adhesive feeding system (43) to spray, release adhesive onto the mattress layer (Y) on said adhesive unit (4), at least one transfer roller (44a) rotatable around itself on the mattress layer (Y) for applying the adhesive flowing from said adhesive feeding system (43) onto the mattress layer (Y), at least one dosing roller (44b) positioned adjacent to said transfer roller (44a) for homogeneous application of the adhesive to its surface, at least one assembly unit (5) for enabling the adhering of the mattress layers (Y) by stacking them one on top of the other following the adhesive unit (4) and in said assembly unit (5), at least one upper conveyor (52) for advancing the mattress layer (Y) and at least one lower conveyor (51) in the lower neighboring area of said upper conveyor (52) for moving the mattress layer (Y), to which adhesive was applied in the previous operation, forward and backward to ensure stacking and at least one internal space (441) through which hot fluid can be passed for heating at least one of the transfer roller (44a) and dosing roller (44b), and at least one heating tank (45) to which it is connected to supply hot fluid to said internal space (441).

Description

[0001] A MATTRESS MANUFACTURING SYSTEM FOR ASSEMBLING MATTRESS LAYERS BY STACKING THEM ON TOP OF EACH OTHER

[0002] TECHNICAL FIELD

[0003] The invention relates to a mattress manufacturing system with at least one adhesive unit for enabling the mattress layers to be adhered together.

[0004] PRIOR ART

[0005] Mattress manufacturing systems refer to the various technologies and processes used for the production of mattresses. These systems cover all stages from the selection of raw materials to the final form of the mattress. Mattress manufacturing systems can vary depending on the degree of automation on the production line, the materials used, and the types of mattresses produced. These systems are aimed at mass production of mattresses, maintaining quality standards, and increasing productivity. In mattress manufacturing systems, adhering the mattress layers is the process of combining and assembling the different layers of the mattress. This process is a very important step that determines the comfort, support, and durability characteristics of the mattress.

[0006] Mattress layers are made up of different materials, usually upper comfort layers, support layers, and base layers. Comfort layers are usually made of soft materials such as foam, latex, or wool, while support layers can be made of more rigid and durable materials, such as high-density foam. The base layer, on the other hand, forms the lower part of the mattress and usually has a more robust structure to support the other layers of the mattress. In the process of adhering the mattress layers, these layers are connected to each other using special adhesives. The adhesives used are generally selected to be harmless to human health, hypoallergenic, and long-lasting. These adhesives ensure that the layers are bonded tightly and that there is no slipping or separation between the layers when using the mattress.

[0007] Application No. US2015203221 A1 known in the art is related to the process of compressing foam products and rolling them into a cylindrical package. The object of the invention is a system designed for packaging foam products, in which system the first side compressor applies pressure to the first side of the foam product, while the second side compressor applies pressure to the second side of the foam product, reducing the width of the foam product by compression. In addition, the system includes a roller device that converts the compressed foam product into a cylindrical packaging product. In this way, the aim is to facilitate the storage and transportation processes of foam products by compressing them to take up less space and turning them into a cylindrical package.

[0008] Water-based adhesives used in adhering mattress layers in mattress manufacturing systems are preferred for their environmentally friendly and non-harmful properties to human health. Water-based adhesives have longer drying times than other adhesives since the water they contain must evaporate, which can prolong the production process and reduce productivity. Furthermore, water-based adhesives, which often have a lower adhesive strength than solvent-based adhesives, may not be ideal for applications that require high durability. These adhesives are also highly affected by moisture. High humidity conditions can adversely affect the adhesion properties, reducing the durability of the product. Water-based adhesives are also sensitive to temperature changes. They can freeze at low temperatures and deteriorate at high temperatures. Storage conditions are also critical for these adhesives; in particular, temperature and humidity levels need to be kept under control, as improper storage conditions can adversely affect the life and performance of the adhesive.

[0009] As a result, all the above-mentioned problems have made it imperative to make an innovation in the relevant technical field.

[0010] SUMMARY OF THE INVENTION

[0011] The present invention relates to a mattress manufacturing system for eliminating the above-mentioned disadvantages and bringing new advantages to the relevant technical field.

[0012] The main object of the invention is to introduce a mattress manufacturing system with improved manufacturing process of a mattress with layers.

[0013] To achieve all the objects mentioned above and that will emerge from the following detailed description, the present invention is a mattress manufacturing system with at least one adhesive unit for enabling the mattress layers to be adhered together. Accordingly, its novelty is that it comprises at least one adhesive feeding system to spray, release adhesive onto the mattress layer on said adhesive unit, at least one transfer roller rotatable around itself on the mattress layer for applying the adhesive flowing from said adhesive feeding system onto the mattress layer, at least one dosing roller positioned adjacent to said transfer roller for homogeneous application of the adhesive to its surface, at least one assembly unit for enabling the adhering of the mattress layers by stacking them one on top of the other following the adhesive unit and in said assembly unit, at least one upper conveyor for advancing the mattress layer and at least one lower conveyor in the lower neighboring area of said upper conveyor for moving the mattress layer, to which adhesive was applied in the previous operation, forward and backward to ensure stacking and at least one internal space through which hot fluid can be passed for heating at least one of the transfer roller and dosing roller, and at least one heating tank to which it is connected to supply hot fluid to said internal space.

[0014] A possible embodiment of the invention is characterized in that it is configured such that the vertical height of the upper conveyor is changed depending on the thickness of the mattress layer on the lower conveyor. Thus, the upper conveyor adapts to the thickness of the mattress layers, ensuring that the layers are placed on top of each other in the correct order and effectively assembled.

[0015] Another possible embodiment of the invention is characterized in that it comprises at least one inner cavity through which hot fluid can be passed for heating at least one of the transfer roller and the dosing roller, and at least one heating tank to which it is connected for supplying hot fluid to said inner cavity. Thus, it is ensured that the adhesive is kept at the ideal temperature and effectively applied to the mattress layers.

[0016] Another possible embodiment of the invention is characterized in that the transfer roller has a larger diameter than the dosing roller and the transfer roller is configured to contact the mattress layer surface. Thus, it is ensured that the adhesive is applied to the mattress layer over a large area and evenly.

[0017] Another possible embodiment of the invention is characterized in that it comprises at least one adjustment element for changing the distance between the transfer roller and the dosing roller. Thus, the amount of adhesive to be applied and the density of dispersion can be precisely adjusted.

[0018] Another possible embodiment of the invention is characterized in that it comprises at least one movement mechanism to which the transfer roller and the dosing roller are connected so that they can be positioned vertically in accordance with the mattress layers of different thicknesses. Thus, the rollers are adjusted according to the thickness of the mattresses layers, ensuring effective adhering.

[0019] Another possible embodiment of the invention is characterized in that it comprises at least one drive conveyor for conveying the mattress layer in the lower adjacent part of the transfer roller. Thus, a smooth and uninterrupted progression of the mattress layer to the adhesive application region is ensured.

[0020] Another possible embodiment of the invention is characterized in that said drive conveyor comprises at least one first part fixed horizontally and at least one second part configured to rotate at least partially with respect to the first part. Thus, easier access and operability are ensured during maintenance and cleaning operations.

[0021] Another possible embodiment of the invention is characterized in that it comprises at least one bridge on which the transfer roller and dosing roller are located, and at least one chassis for carrying said bridge. Thus, the structural integrity and durability of the adhesive unit are increased.

[0022] Another possible embodiment of the invention is characterized in that the adhesive is either a PUR-based adhesive or a water-based adhesive. Thus, it is possible to select adhesives suitable for the different properties and requirements of the mattress layers, and a more flexible and effective adhering process is provided.

[0023] Another possible embodiment of the invention is characterized in that it comprises following the assembly unit at least one pressing unit for compressing the mattress layers towards each other. Thus, it is ensured that the mattress layers are firmly adhered together, thereby increasing the integrity and durability of the product.

[0024] BRIEF DESCRIPTION OF THE DRAWING Fig. 1 shows a representative perspective view of the mattress manufacturing system of the invention.

[0025] Fig. 2 shows a representative perspective view of the adhesive unit in the mattress manufacturing system of the invention.

[0026] Fig. 3 shows a representative perspective view of the adhesive unit in the mattress manufacturing system of the invention.

[0027] Fig. 4 shows a representative perspective view of the adhesive unit in the mattress manufacturing system of the invention.

[0028] Fig. 5 shows another representative perspective view of the adhesive unit in the mattress manufacturing system of the invention.

[0029] Fig. 6 shows a representative cross-section C-C view of the adhesive unit in the mattress manufacturing system of the invention.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031] In this detailed description, the subject of the invention is explained by way of example only for a better understanding of the subject, which shall not create any limiting effect.

[0032] Fig. 1 shows a representative perspective view of the mattress manufacturing system (1 ) of the invention. Accordingly, the mattress manufacturing system (1 ) of the invention consists of a series of robotic and mechanical units that automate the production and installation process of the mattress layers (Y). The mattress manufacturing system (1 ) is configured to place the mattress layers (Y) in the correct order and position, apply adhesives, assemble and compress the mattress layers (Y), and cut off excesses. The automated mattress manufacturing system (1 ) increases the speed and efficiency of the production process, while reducing the error rate and ensuring the consistency of product quality. In this way, the manufacture of mattresses is carried out more economically, quickly, and with high quality. Accordingly, the mattress manufacturing system (1 ) of the invention comprises a robotic arm (2) that feeds the mattress layers (Y) in a certain order, a straightening conveyor (3) on which said robotic arm (2) places the mattress layer (Y), an adhesive unit (4) which can apply adhesive to the mattress layers (Y) following the straightening conveyor (3), an assembly unit (5) for stacking the mattress layers (Y) one on top of the other following the adhesive unit (4), a lower conveyor (51 ) and an upper conveyor (52) for arranging the mattress layers (Y) one on top of the other in the assembly unit (5). It is configured to comprise a pressing unit (6) for pressing the mattress layers (Y) into a tight adhesion, a cutting unit (7) following the pressing unit (6) for cutting and cleaning the waste parts at the edges of the mattress. Each unit plays a critical role in the production and installation process of the mattress layers (Y) and works in cooperation with each other to increase the efficiency of the production line and product quality.

[0033] The robotic arm (2) in the mattress manufacturing system (1 ) picks up the mattress layers (Y) using a programmable mechanism and places them on the straightening conveyor (3) in the specified order. By means of the robotic arm (2), the layers that make up the mattress (Y) are continuously fed to the line in order. The robotic arm (2) can precisely carry mattress layers (Y) of different dimensions and weights, minimizing human error. The robotic arm (2) reduces labor costs and increases the speed and repeatability of the production process.

[0034] The straightening conveyor (3), on which the mattress layers (Y) are placed, allows each mattress layer (Y) to be fed into the adhesive unit in the correct position. For this purpose, there can be pusher units on opposite sides of the straightening conveyor (3) to center the mattress layers (Y). Thus, the centering of the mattress layers (Y) is achieved. The straightening conveyor (3) aligns the edges of the mattress layers (Y) and prepares an ideal surface for the adhering process.

[0035] Fig. 2 shows a representative perspective view of the adhesive unit (4) in the mattress manufacturing system (1 ) of the invention. The adhesive unit (4) applies adhesive on the mattress layers (Y) in a controlled manner. The adhesive unit (4) ensures that the adhesive is evenly distributed, helping the layers to form a strong and homogeneous bond with each other. The type and amount of adhesive can be adjusted according to the material properties and adhesion requirements of the mattress layers (Y). The assembly unit (5) is configured to place adhesive-applied mattress layers (Y) in the correct order on top of each other using at least one lower conveyor (51 ) and at least one upper conveyor (52). Conveyors are positioned one above the other to continuously move the mattress layers (Y) back and forth. The upper conveyor (52) and the lower conveyor (51 ) are essentially positioned one above the other in the vertical direction. The upper conveyor (52) is configured to continuously move the mattress layer (Y) forward, while the lower conveyor (51 ) moves the previously moved mattress layer (Y) both forward and backward. In this way, the lower conveyor (51 ) is capable of placing the leading mattress layer (Y) under the next mattress layer (Y) of the mattress layers (Y) being transported respectively. Thus, it makes assembling the mattress layers (Y) by stacking them on top of each other possible. Thus, the adhesive performs its function effectively, and it is ensured that air bubbles do not form during the assembly of the mattress layers (Y) and that there are no gaps between the mattress layers (Y). In the assembly unit (5), the upper conveyor (52) is configured such that it can be at least partially displaced vertically relative to the lower conveyor (51 ). This is because the height of the mattress layer (Y) placed on the lower conveyor (51 ) changes constantly. The upper conveyor (52) positions itself vertically depending on the thickness of the mattress layer (Y), ensuring that the mattress layers (Y) are precisely stacked on top of each other.

[0036] The pressing unit (6) compresses the assembled mattress layers (Y) under a certain pressure, allowing the adhesive to penetrate and harden well between the mattress layers (Y). This process helps to strengthen the adhesive bonds and ensure that the mattress layers (Y) adhere firmly to each other. The pressing time and pressure can be adjusted according to the type of adhesive and the properties of the mattress layers (Y). The cutting unit (7) then cuts off the excess edges of the pressed mattress layers (Y) and creates the final dimensions of the mattress. This process ensures that the mattress has clean and smooth edges and enhances the aesthetic appearance of the product. The cutting process is carried out with high precision and can be adjusted according to the dimensions of the mattress.

[0037] Fig. 3, 4, and 5 show a representative perspective view each of the adhesive unit (4) in the mattress manufacturing system (1 ) of the invention. Accordingly, the adhesive unit (4) has at least one chassis (41 ) and at least one bridge (42) on said chassis (41 ). Said chassis (41 ) is the structure that forms the basis of the entire adhesive unit (4). It is preferably made of metal or a similar material and has the function of carrying all other components of the adhesive unit (4). The chassis (41 ) also ensures that the adhesive unit (4) remains stable against movements and vibrations in the manufacturing environment and increases the precision of the adhering process. The bridge (42) is located on the chassis (41 ) and is shaped in an inverted U-shape. The bridge (42) carries at least one adhesive feeding system (43), at least one transfer roller (44a)-dosing roller (44b), and at least one movement mechanism (47).

[0038] From the adhesive feeding system (43), the adhesive is released and sprayed on the mattress layer (Y). This adhesive feeding system (43), which can be present in multiple numbers on the bridge (42), applies the PUR (polyurethane) based adhesive onto the mattress layers (Y). PUR based adhesive is solid under normal conditions. To do this, a PUR based adhesive is heated beforehand. To enable this, the adhesive feeding system (43) is associated with at least one heating tank (45).

[0039] Fig. 6 shows a representative cross-section view of the adhesive unit (4) in the mattress manufacturing system (1 ) of the invention. There are at least two rollers, preferably on the bridge (42), on either side of the adhesive feeding system (43). One of these rollers is a dosing roller (44b) and a transfer roller (44a). The transfer roller (44a) and the dosing roller (44b) are preferably of different diameters. The transfer roller (44a) is preferably larger in diameter than the dosing roller (44b). The larger diameter transfer roller (44a) is placed in contact with the mattress layer (Y), while the dosing roller (44b) ensures that the adhesive is homogenously spread over the larger diameter transfer roller (44a). The adhesive flowed through the adhesive feeding system (43) is flowed between the transfer roller (44a) and the dosing roller (44b). The distance between the transfer roller (44a) and the dosing roller (44b) can be changed according to the need by means of an adjustment element (46). In this way, the amount of adhesive used per unit area becomes adjustable. In a preferred embodiment of the invention, the transfer roller (44a) and the dosing roller (44b) are manufactured in different diameters so that the transfer roller (44a) applies the adhesive on the mattress layer (Y) while the dosing roller (44b) allows the adhesive to be homogenously distributed on the transfer roller (44a). However, in an alternative embodiment of the invention, the transfer roller (44a) and the dosing roller (44b) may be of equal diameter. In this case, it can be positioned higher vertically to prevent the dosing roller (44b) from coming into contact with the mattress layer (Y). In this way, it can be ensured that only the transfer roller (44a) is contacted on the mattress layer (Y). In a possible embodiment of the invention, at least one roller may be associated with a roller drive element (442) for rotating at least one of the rollers around itself. This roller drive element (442) is two pieces, preferably separately for the dosing roller (44b) and the transfer roller (44a). In this context, by rotating the dosing roller (44b) at different speeds compared to the transfer roller (44a), less adhesive is applied on the mattress layer (Y) and a more effective adhesive function is achieved. In another possible embodiment of the invention, there are multiple dosing rollers (44b), two in particular. Thanks to this process, efficient adhesion can be achieved with a lower amount of adhesive.

[0040] It ensures that the adhesive sprayed by the adhesive feeding system (43) of the mattress layers (Y) is uniformly impregnated onto the mattress layer (Y). heating the transfer roller (44a) and the dosing roller (44b) helps the mattress layers (Y) to be bonded more effectively with the adhesive. To allow this, at least one of the transfer roller (44a) and the dosing roller (44b) has at least one internal space (441 ). Said internal space (441 ) is sized such that the hot fluid can pass through. In a possible embodiment of the invention, the internal space (441 ) can be in the form of a channel in the roller. In an alternative embodiment of the invention, the internal space (441 ) can also be provided between the diameter spaces between the two interconnected pipes of the roller. In this way, the desired temperature can be transferred to the rollers with less fluid. This internal space (441 ) ensures that the transfer roller (44a) and dosing roller (44b), and thus the mattress layers (Y), are at a homogeneous temperature during the adhering process. The internal space (441 ) is provided in both the transfer roller (44a) and the dosing roller (44b) in the preferred use of the invention. To enable this, the internal space (441 ) is connected with at least one heating tank (45). The heating tank (45) is the heating device used to ensure that the hot fluid reaches the ideal level of fluidity. The heating tank (45) adjusts the hot fluid in a predetermined manner, which is critical for the adhesive to be applied and spread uniformly between the layers. An interconnection part (49) can be used to ensure flow integrity between the transfer roller (44a) and dosing roller (44b) and the heating tank (45). In this way, it is ensured that a sealed connection can be established therebetween.

[0041] The movement mechanism (47) allows the vertical height of the transfer roller (44a) and the dosing roller (44b) to be adjusted, adapting to different thickness of mattress layers (Y). The movement mechanism (47) enables the transfer roller (44a) and the dosing roller (44b) to move in the vertical axis, which allows the adhering process to be applied in accordance with the different mattress layers (Y). To enable this, the movement mechanism (47) has at least one drive element (471 ) positioned on the bridge (42). Said drive element (471 ) moves the transfer roller (44a) and the dosing roller (44b) vertically by means of at least one reducer (472) and the movement transmission arms (473). The transfer roller (44a) and the dosing roller (44b) are associated with at least one ball screw (474) on each opposite side. The vertical movement can be controlled by rotating the ball screw (474) around itself by the drive element (471 ).

[0042] There is at least one drive conveyor (48) on the adhesive unit (4) in the lower adjacent part of the transfer roller (44a). Said drive conveyor (48) allows the forward movement of the mattress layer (Y) on the adhesive unit (4). The drive conveyor (48) essentially contains a first part (481 ) and a second part (482) to facilitate maintenance. Said first part (481 ) is essentially located in the lower vertical adjacent part of the transfer roller (44a) and is kept fixed horizontally. The second part (482) is adjacent to the first part (481 ) and is configured to rotate at least partially. The second part (482) can be rotated at least partially in case of maintenance, allowing the operator to clean the adhesive unit (4).

[0043] The mattress manufacturing system (1 ) of the invention is notable for its adhesive unit (4), which focuses especially on the use of PUR (polyurethane) based adhesives. Compared to water-based adhesives, PUR-based adhesives offer high adhesion strength and superior durability properties, resulting in tighter and more permanent assembly of the mattress layers (Y). The adhesive unit (4) in the system is designed to apply this special adhesive homogeneously and in the right quantities to the mattress layers (Y). The heated transfer roller (44a), the dosing roller (44b), and the specially configured adhesive feeding systems (43) guarantee that the PUR adhesive is effectively applied to the mattress layers (Y) while maintaining the ideal temperature and viscosity. This approach improves quality and durability in mattress production, while eliminating moisture issues that can be caused by water-based adhesives and the risk of not providing sufficient adhesive strength. In addition, the mattress manufacturing system (1 ) subject to the invention can also be used for water-based adhesives in alternative embodiments of the invention. This system takes the mattress production process to a new level in terms of efficiency and quality, offering significant advantages to manufacturers and end users. The scope of protection of the invention is specified in the appended claims and cannot be limited to what is described for illustrative purposes in this detailed description. It is clear that a person skilled in the art can produce similar embodiments in the light of what is explained above, without deviating from the main theme of the invention.

[0044] REFERENCE NUMERALS GIVEN IN DRAWING

[0045] 1 Mattress Manufacturing System

[0046] 2 Robotic Arm

[0047] 3 Straightening Conveyor

[0048] 4 Adhesive Unit

[0049] 41 Chassis

[0050] 42 Bridge

[0051] 43 Adhesive Feeding System

[0052] 44a Transfer Roller

[0053] 44b Dosing Roller

[0054] 441 Internal Space

[0055] 442 Roller Drive Element

[0056] 45 Heating Tank

[0057] 46 Adjustment Element

[0058] 47 Movement Mechanism

[0059] 471 Drive Element

[0060] 472 Reducer

[0061] 473 Movement Transmission Arm

[0062] 474 Ball Screw

[0063] 48 Drive Conveyor

[0064] 481 First Part

[0065] 482 Second Part

[0066] 49 Interconnection Part

[0067] 5 Assembly Unit

[0068] 51 Lower Conveyor

[0069] 52 Upper Conveyor

[0070] 6 Pressing Unit

[0071] 7 Cutting Unit Y Mattress Layer

Claims

CLAIMS1. A mattress manufacturing system (1 ) with at least one adhesive unit (4) for enabling the mattress layers (Y) to be adhered together, characterized in that it comprises at least one adhesive feeding system (43) to spray, release adhesive onto the mattress layer (Y) on said adhesive unit (4),At least one transfer roller (44a) rotatable around itself on the mattress layer (Y) for applying the adhesive flowing from said adhesive feeding system (43) onto the mattress layer (Y), at least one dosing roller (44b) positioned adjacent to said transfer roller (44a) for homogeneous application of the adhesive to its surface, At least one assembly unit (5) for enabling the adhering of the mattress layers (Y) by stacking them one on top of the other following the adhesive unit (4), In said assembly unit (5), at least one upper conveyor (52) for advancing the mattress layer (Y) and at least one lower conveyor (51 ) in the lower neighboring area of said upper conveyor (52) for moving the mattress layer (Y), to which adhesive was applied in the previous operation, forward and backward to ensure stacking, and at least one internal space (441 ) through which hot fluid can be passed for heating at least one of the transfer roller (44a) and dosing roller (44b), and at least one heating tank (45) to which it is connected to supply hot fluid to said internal space (441 ).

2. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it is configured such that the vertical height of the upper conveyor (52) is changed depending on the thickness of the mattress layer (Y) on the lower conveyor (51 ).

3. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that the transfer roller (44a) has a larger diameter than the dosing roller (44b) and the transfer roller (44a) is configured to contact the mattress layer (Y) surface.

4. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it comprises at least one adjustment element (46) for changing the distance between the transfer roller (44a) and the dosing roller (44b).

5. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it comprises at least one movement mechanism (47) to which the transfer roller(44a) and the dosing roller (44b) are connected so that they can be positioned vertically in accordance with the mattress layers (Y) of different thicknesses.

6. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it comprises at least one drive conveyor (48) for conveying the mattress layer (Y) in the lower adjacent part of the transfer roller (44a).

7. A mattress manufacturing system (1 ) according to Claim 6, characterized in that said drive conveyor (48) comprises at least one first part (481 ) fixed horizontally and at least one second part (482) configured to rotate at least partially with respect to the first part (481 ).

8. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it comprises at least one bridge (42) on which the transfer roller (44a) and dosing roller (44b) are located, and at least one chassis (41 ) for carrying said bridge (42).

9. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that the adhesive is either a PUR-based adhesive or a water-based adhesive.

10. A mattress manufacturing system (1 ) according to Claim 1 , characterized in that it comprises following the assembly unit (5) at least one pressing unit (6) for compressing the mattress layers (Y) towards each other.

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