Improved foam spring for pillows, cushions, mattresses or the like and a method for manufacturing such a foam spring

Field of technology

The present invention relates to an improved spring element made of synthetic foam, more particularly to an improved spring element characterized by a tubular elastic body made of synthetic foam. In the tubular body of the spring element in question, openings are made which extend from the outer to the inner surface of said tubular body. The spring element in question can be used to make the cores of pillows, cushions, mattresses and similar products.

The present invention also relates to a process for the production of said improved spring element from synthetic foam.

Technical problem

The technical problem solved by this patent application is: how to make a spring element in which the lateral deformation would be prevented, ie the bulge of the spring element during its compression under load, even when a synthetic foam of lower density is used to make the body of the spring element. the need to install a metal spring or additional reinforcements in the body of the spring element.

State of the art in the technical field

Synthetic foam spring elements are discussed, for example, in patent solution EP 0.001.469, published by the European Patent Office, in which, in addition to the characteristics of the described element, details of its manufacture are given. The elements described in the mentioned innovation mainly consist of a tubular body made of synthetic foam or similar material, in the wall of which a number of cavities are made, which follow a chess, ie zigzag arrangement. The cross section of the cavities varies practically from zero, as it is on the inner side of the wall of the tubular body of the spring element, to the maximum value present on the outer wall of the tubular body of the element, where the mentioned values ​​are characteristic for the state when the spring element is not under load.

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In order to achieve the desired elasticity of the spring element, within the above-described solution, it is proposed to place at least one core of elastic spring material within the tubular body of the element, such that the core diameter corresponds to the inner diameter of the tubular body of the element.

Also, the patent solution EP 0.624.332, published by the European Patent Office, describes an elastic spring element consisting of a tubular body made of synthetic foam, in which openings are made which extend from the outer to the inner surface of said body of the element. . Said element also comprises a metal spring housed in the previously described synthetic foam tubular body.

Unlike the elastic spring element made entirely of synthetic foam, the aforementioned innovation states that the use of ordinary and therefore less expensive types of synthetic foam for the purpose of making the tubular body of the spring element, within which the metal spring is located above, does not reduce hardness registered when testing material fatigue.

In addition, Patent Decision 2005/0172468, published by the United States Patent Office, describes a process for making a tubular elastic body for making pillows, mattresses and similar products. The subject method comprises making a slit in the prepared layer of synthetic foam, from which, in the further course of the process, a strip of foam is cut off whose opposite ends are joined to form the desired tubular shape of the subject elastic body. The mentioned layer of foam that is used for the production of the described tubular elastic body is the so-called layer. viscoelastic memory foam. In addition, said viscoelastic memory foam is at least partially derived as an open cell structure foam.

In a preferred embodiment of the above-described patent solution, it is preferred that the fabricated tubular body be of a biconical or approximately biconical external shape.

In the framework of the previously mentioned innovation, it is stated that elastic bodies made of synthetic foam of low specific weight, such as the tubular elastic bodies described above, retain their elastic properties during a shorter period of practical use, as a result of which they have the ability to

53253 Β in case of their application in the production of pillows or similar end products, they retain their functionality for a longer period of time.

Also, in the patent solution EP 0.872.198, published by the European Patent Office, spring elements made of synthetic foam are described, which consist of a tubular body made of synthetic foam, in the walls of which recesses are made which extend from the outer to the inner surface. said wall of the tubular body of the element. The described tubular body expands from one end to the other, thus taking on a drum shape in the case when the said body is round in initial shape.

The main advantage of the mentioned spring elements is the lower fatigue of the material compared to the solutions used in previous practice, as well as the ability of the spring elements in question to maintain the initial height and shape during their shorter useful life.

The spring elements of synthetic foam described in International Patent Solution WO 2009/036524 are also known in practice. The subject elements, intended for use in the manufacture of pillows, mattresses and similar products, are characterized by a tubular elastic body made of synthetic foam in which openings are made directed from the outer to the inner surface of the said tubular body. In this case, said tubular body comprises at least one layer of synthetic tubular foam and at least one reinforcing layer which is placed over said foam layer on at least a part of the total axial length of the spring element in question.

Within the scope of the mentioned patent solution, it is stated that the elastic characteristics of the described spring element can be easily modified by using a reinforcing layer which is characterized by an appropriate tensile resistance.

Although end users appreciate when the described spring elements made of synthetic foam are used in the manufacture of pillows, mattresses and similar products, the lack of these elements is reflected in the need to make a spring element with a precisely defined external shape, which complicates their dense and compact packaging. additional components, such as metal springs, reinforcing core, special support supports or reinforcing layers that significantly complicate and increase the cost of production of the described elements, requiring the consumption of a larger amount of energy and causing significant environmental pollution.

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An additional disadvantage of these elements is the risk of minor damage, which can occur, for example, during their manufacture, packaging, storage, transport, installation and similar operations or during the final production of pillows, mattresses or similar end products. The stated danger of damage occurs primarily as a consequence of the exposure of the spring element to tensile forces of high intensity.

As a result, the manipulation of the mentioned spring elements must be performed carefully and carefully, which significantly slows down the process of their production and increases the production costs.

An additional disadvantage of the considered spring elements is their pronounced tendency towards lateral deformation, ie convexity during compression of the element in the axial direction, which is directly reflected in the working performance of adjacent spring elements.

Due to all the above, the elastic performance of individual spring elements built into a pillow, mattress or similar end product is sometimes difficult to predict, so adapting a pillow, mattress or similar product to the individual needs of users is not an easy task.

Statement of the essence of the invention

It is an object of the present invention to provide a spring element of synthetic foam with improved characteristics, suitable for use in the manufacture of cushions, mattresses and the like end products, wherein the spring element of the present embodiment does not have any of the above disadvantages or other disadvantages.

Detailed description of the invention

According to the preceding, the present patent solution relates to a spring element 1 of synthetic foam intended for use in cushions, cushions, mattresses and similar end products. Said spring element consists of a tubular elastic body 2 made of synthetic foam which acts as an outer wall of the subject element 1. In the wall of the tubular body 2, in the direction from its outer surface 4 to the inner surface 5, openings 3 are made mainly in a zigzag pattern. symmetry i.e. rhomboid shape. The openings 3 in the wall of the tubular body 2 follow a chess or zigzag arrangement and are present in only one number of segments 16 of the outer

53253 Β the surfaces of the tubular body 2 of the spring element 1. Said segments 16 of the outer surface 4 on which the openings 3 are made alternately with the segments 18 of the outer surface 4 on which no openings 3 are made and which in the described configuration act as longitudinal ribbed reinforcements 7 of the tubular body 2 of the subject spring element 1.

The main advantage of the described embodiment is reflected in the significantly improved distribution of the compressive stress in the spring element 1 during the action of the load. This is achieved precisely by means of said ribbed reinforcements 7 and their even distribution over the circumference of the tubular body 2 of the spring element 1. This configuration eliminates the need to install a metal spring or additional reinforcements in the body of the spring element, by using layers of synthetic foam of different densities or by applying similar solutions known in modern practice.

In addition, the ribbed reinforcements 7 made in accordance with the present invention more effectively prevent lateral deformation, ie bulging of the spring element during its compression under the action of a load, even when a lower density synthetic foam is used to make the body of the spring element.

The use of synthetic foam of lower density for the production of the considered spring element 1, without disturbing its basic static and dynamic characteristics, not only reduces the amount of energy required for processing the basic raw material, reduces production costs and shortens the time required to produce the spring element 1, but in the case where said spring element 1 is used to make a cushion, pads and similar products also provide better comfort and adaptation of synthetic foam to the body shape of the end user.

In this way, equal or even better static, dynamic and long-term performance of the spring element 1 can be achieved in a much simpler and more economical way than by using the spring elements applied in current practice.

The main advantage of the described solution is reflected in the fact that the ribbed reinforcements 7 in the proposed embodiment of the present invention represent an integral part of the tubular body 2 of the spring element 1. In this case, said ribbed reinforcements 7 are produced in a single production step, thus avoiding potential production problems. for adhesion, layering, procurement and storage of individual components and the like.

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An additional advantage, which arises as a result of the above, is reflected in the lower tendency of the described spring elements to damage caused by careless handling during the production and manufacture of pillows, mattresses and similar end products.

Based on all the above, it can be concluded that the described spring elements do not require special careful manipulation to prevent possible damage during their manufacture, assembly, handling, storage, installation, etc., which allows faster production and reduction of scrap in the production process.

In the proposed embodiment of the subject element 1, the longitudinal ribbed reinforcements 7 prevent the elastic characteristics of each individual spring element from being affected by the elastic characteristics of adjacent compressed spring elements, thus allowing the expected elastic performance of each individual spring element used to make cushions, mattresses and the like. predict with greater certainty.

Due to the possibility of more reliable prediction of the expected elastic performance of each individual spring element, making pillows, mattresses and similar products and adapting them to specific needs, ie the shape and weight of the end user becomes easier, which results in better comfort and greater comfort for the end user.

An additional advantage of the proposed embodiment of the spring element 1 is reflected in the greater resistance of the subject element to damage that may occur during the manufacture of pillows, mattresses or similar products, which is achieved by the presence of ribbed reinforcements 7 evenly distributed around the circumference of the spring element 1. structural elements, for example metal springs, in the tubular body of the element. This also significantly reduces the weight and complexity of the design of the subject elements.

An additional advantage of the proposed embodiment is the possibility of adjusting the elastic performance of the spring element, which is achieved not only by the correct choice of raw materials and synthetic foam made of them, but also by the relative ratio of surfaces of segments 16 of tubular body 2 on which holes 3 and segments 18 on which no openings 3 are made, as well as their geometric position and arrangement along the body of the spring element 1.

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The spring elements which are the subject of the invention can, of course, also be combined with other types of springs in order to form different comfort zones in the cushion, mattress or similar end product, which are characterized by different softness of the material.

In a preferred embodiment of the present invention, the segments 18 of the tubular body 2 of the spring element 1 on which no openings 3 are made and which form a plurality of ribbed reinforcements 7 in the wall of the tubular body 2 extend from the base to the top of the tubular body 2 of the spring element 1.

In a preferred embodiment of the present invention, the width of the segment 16 of the tubular body 2 of the spring element 1 on which the openings 3 are made is equal to the width of the segment 18 of the tubular body 2 on which no openings 3 are made, said dimensions referring to the case of undeformed foam layer.

In a preferred embodiment of the present invention, the openings 3 made on the segment 16 of the tubular body 2 follow a checkerboard or zigzag arrangement and not only one relative to the other, but are arranged in the same way in relation to the openings 3 made in any adjacent segment. 16 of a tubular body 2 on which said openings 3 are formed, wherein the adjacent segments 16 with the derived openings 3 are separated from each other by segments 18 of the tubular body 2 on which the openings 3 are not made.

In a preferred embodiment of the present invention, the outer surface 4 of the segment 18 of the tubular body 2 on which no openings 3 are made has a sinusoidal shape, in part or along the entire axial length of the spring element.

In a preferred embodiment of the present invention, the non-perforated segments 18 of the tubular body 2, i.e. the segments 18 on which no openings 3 are made, act as ribbed reinforcements 7 which are evenly distributed around the circumferential tubular body 2 and along the longitudinal axis H-H 'of the described spring element 1.

In a preferred embodiment of the present invention, the number of segments 18 of the tubular body 2 of the spring element 1 on which no openings 3 are made and which act as ribbed reinforcements 7 in the wall of the tubular body 2 of the element 1 is between 4 and 12, preferably between 6 and 10, and most preferably 8 .

In a preferred embodiment of the present invention, the spring element 1 comprises a strip 8 with at least one layer 6 of synthetic foam and a series of slits 17 extending along one particular

53253 Β directions and which are surrounded by surfaces without made slots 17. On the strip 8, in the direction of the mentioned slots 17, two opposite kgaja 11-12 are separated. Said opposite ends 1112 of the strip 8 are bent and brought to each other, in order to be glued together and thus form the previously mentioned hollow tubular body 2 of the spring element 1, as well as to make the rhomboid shape obtained as a result of stretching the slit 17. in the transverse direction during the mentioned bending of the strip 8. In this case, the segments 18 of the spring element 1 on which no slits 17 are made take the role of ribbed reinforcements 7 which are evenly distributed around the circumference of the tubular body 2 and aligned along the longitudinal axis H-H 'of the spring element

1.

In a preferred embodiment of the present invention, the slots 17 in the strip 8 of the spring element 1 are made with regular breaks along a number of parallel columns 13.

In a preferred embodiment of the present invention, the slits 17 in the strip 8 of the spring element 1 follow a checkerboard pattern, wherein the slits 17 made along adjacent columns 13 are displaced relative to each other in the longitudinal direction H-H '.

In a preferred embodiment of the present invention, the slots 17 in the strip 8 of the spring element 1 made in two adjacent segments 16 with slots 17, which are separated by a segment 18 of the spring element 1 on which no slots 17 are made, are also arranged in a checkerboard pattern. -even the arrangement, wherein the slits 17 made along the adjacent columns 13 are displaced, ie offset from each other in the longitudinal direction H-H '.

The present invention also relates to a process for the production of a spring element 1 formed of synthetic foam, characterized by an elastic tubular body 2 and intended for use in the manufacture of pillows, mattresses and the like. The present method comprises making slits 17 in the synthetic foam layer 6, which are arranged intermittently along the columns 13 which extend in the longitudinal direction H-H 'along at least a number of segments of said synthetic foam layer 6. The segments 16 with properly spaced slots 17 alternate with adjacent segments 18 of the synthetic foam layer 6 on which no slits 17 have been made. In the further course of the present procedure, a strip of foam 8 is cut transversely from said synthetic foam layer 6, whose opposite ends 11 -12 bend and converge with each other in order to join and form a tubular shape, ie a tubular elastic body 2 of the subject spring element 1. On the outer side and along the longitudinal axis H-H 'formed

53253 Β of the tubular body 2, the segments 16 on which the slots 17 are made and the adjacent segments 18 on which no slots 17 are made are alternated, whereby the segments 18 without the made slots 17 have the role of longitudinal ribbed reinforcements 7 in the tubular body 2 of the spring element 1.

Description of draft images

In order to better understand the characteristics of the present innovation, the preferred embodiment and method of making the spring element which is the subject of the invention are described in more detail below, the described embodiment being only one of the possible variants of the present innovation. The present invention will be described with reference to the figure below, of which:

Figure 1 shows a perspective drawing of a spring element 1 of synthetic foam which is the subject of the invention;

Figure 2 shows a layer 6 of synthetic foam with evenly spaced segments (16) on which slots 17 are made, which alternately alternate with segments (18) without made slots 17, said layer of synthetic foam 6 being used to make a spring element 1 of synthetic foam which is the subject of the invention.

Description of the preferred variant

The spring element shown in Figure 1 represents a spring 1 made of synthetic foam intended for use in pillows, cushions, mattresses and similar end products. Said element comprises a tubular elastic body 2 in which openings 3 are made, which extend from the outer surface 4 to the inner surface 5 of the tubular body 2 of the spring element 1.

The tubular body 2 of the spring element 1 comprises a layer 6 of synthetic foam.

In a preferred embodiment of the present invention, the openings 3 made in the tubular body 2 of the spring element 1 are made in a regular, zigzag arrangement.

Said configuration allows any deformation of the spring element 1 along the direction indicated by the arrow P, which occurs when compressing said element, to be equal

53253 Β distributed ρο the whole body of the spring element 1. In this way, the radial deformation, ie the bulge of the spring element 1 is limited and prevents the compressive forces from being concentrated in only one part of the element 1, instead of being evenly distributed over the entire tubular body 2.

The segments 16 of the tubular body 2 (shown in Figure 2) on which the said openings 3 are made alternately with the segments 18 of the tubular body 2 on which no openings 3 are made. The segments without openings 18 have the function of ribbed reinforcements 7 which are evenly distributed. by circumference of the tubular body 2.

In a preferred embodiment of the present invention, the ribbed reinforcements 7 are in the form of a sinusoidal wave or a shape following a continuous Z or S line extending in the longitudinal direction H-H ', which is shown in Figure 1 by a dashed line 14.

The advantage of the spring element 1 of synthetic foam shown in Figure 1 is reflected in the absence of the tendency of said element to deformation, ie bulge in the radial or longitudinal direction when compressed in the axial direction H-H ', ie in the direction indicated by arrow P. This feature ensures that the diameter of the tubular spring element in question remains unchanged during its compression.

An additional advantage of the proposed embodiment of the present invention is the improved characteristics in terms of elasticity, compressive strength and useful life of the spring element 1. These improvements are realized even when a synthetic density of lower density is used to make the spring element in question.

Figure 2 shows a layer 6 of synthetic foam from which, in accordance with the described patent solution, a spring element 1 is made of synthetic foam.

The process of making a spring element 1 from synthetic foam is relatively simple and consists of the steps described below.

In the first step of making the spring element 1, a rectangular strip of foam 8 is cut from the prepared layer of synthetic foam. The formed strip 8 is characterized by an axis of symmetry H-H 'and parallel side walls 9-10 and 11-12.

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On the strip 8 there are segments 16 on which slits 17 are made, said segments extending in a direction parallel to said axis of symmetry H-H '. Said segments alternate with segments 18 on which no slots 17 are made.

The slits 17 in the strip 8 are arranged with intermittent breaks along a number of parallel columns 13, wherein within each column 13 the slits 17 are made at equal distances from each other.

The slits 17 are designed to follow a regular, zigzag arrangement, with the slits 17 made along two adjacent columns 13 shifted, ie offset from each other in the longitudinal direction H-H ', for example by a length corresponding to half the length slot 17.

In order to form the tubular body 2 of the spring element 1, the strip 8 is bent in the direction shown in Figure 2 by the dashed line 15.

In this way, the side walls 11 and 12 are brought close to each other so that, in the next step of the process of making the spring element 1, said walls are joined, for example by gluing, and thus form a tubular body 2 of the spring element 1.

As a result of the above steps, the strip 8 is stretched and the slits 17 are opened wide to form the aforementioned openings 3, which extend radially through the tubular body 2 of the element 1 and alternately with ribbed reinforcements 7 formed by adjacent segments 18 on which have no slots 17 and on which, as a result, after the formation of the tubular body 2 there will be no openings 3.

If the slots 17 along several columns 13 are made to follow a zigzag arrangement, not only in relation to each other, but also in relation to the slots 17 made in the adjacent segment 16, which is separated from the previous segment 16 with slots 17 segment 18 on which no slits 17 are made, ribbed reinforcements 7, which are formed in the later stage of production and which are shown in Figure 1, acquire a sinusoidal shape, ie the shape shown in Figure 1 by the dashed line 14.

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Said wave or sinusoidal shape of ribbed reinforcements 7, in accordance with the proposed patent solution, is particularly suitable for converting any bending of the spring element 1, which may occur due to the action of compression forces in the direction indicated by arrow P, into tangential deformation of sinusoidal ribbed reinforcements 7. In this way, the radial bulge of the spring element 1 and all the previously mentioned negative phenomena that may result therefrom are prevented.

Although in a preferred embodiment of the present invention the ribbed reinforcements 7 extend along the entire axial length L of the spring element 1, in one of the possible embodiments of the present invention the ribbed reinforcements 7 can be provided only along a part of the axial length L of the spring element 1. on cylindrical spring elements 1, it can already be applied for the production of spring elements of a different shape.

The previously described configurations and manufacturing process are only an example of possible embodiments and solutions within the present invention, noting that it is possible to devise a number of alternative configurations of said synthetic foam spring element and manufacturing methods that would remain within the scope of the present invention.