EP0796580B1 - Spring core for cushion - Google Patents

Abstract

The core comprises a large number of springs (4) which are inserted in the central foam body (3), on which there are covering layers. The body is profiled on both sides and has protrusions (5) and recesses of a mating geometrical shape. The springs are accommodated in the recesses. Parallel ribs, which can be of trapezium or rectangular cross-section, can be formed on both sides of the body, and spiral springs can be used, their ends resting on the protrusions. The covering layers (2) can be glued to the protrusions, with the spring ends between them. The spring ends can be 60 mm. diameter, or the springs may be of a double-cone shape.

Description

The present invention relates to a spring core according to Claim 1 and in particular with a multi-layer spring core a central foam body in which a variety of spring elements are used, as well as a cushion element with such a spring core.

Such spring cores are used in the furniture industry and are used in particular as the centerpiece in mattresses or upholstered furniture. These key elements are decisive for the durability and hardness of furniture and are usually with a lying or sitting comfort determining padding layer before it with a solid drell are covered. With modern innersprings are for cost reasons, next to foam rubber or foamed Latex, synthetic foams are increasingly used. Unfortunately, the compression hardness leaves and thus the spring force of these foams noticeably after a short time makes this for use in heavily used Unsuitable pieces of furniture. There are improved innersprings therefore from a combination of foam and spring elements.

So today, for example, in railway or airplane seats Spring cores used where metallic springs are used directly are foamed in a foam body. So that can compared to pure foam innersprings, the service life be extended; comfortable and inexpensive However, seating or reclining furniture cannot be made with it become. The direct foaming of the spring elements requires elaborate machine tools and make production more expensive, especially with smaller production quantities. Furthermore it proves to be essential for the comfort of lying and seating furniture that this has good point elasticity have, i.e. have a pronounced local spring force. By foaming the spring elements however, these are coupled with each other and can local load profile is no longer independent of one another consequences. In addition, this type of composite spring core suffers the foam in the area of the metallic spring elements and need these composite spring cores when used heavily to be replaced frequently.

DE-A-2'820'282 describes cushions made of foamed material, e.g. made of foamed polyurethane, with in the upholstery described spring elements and cavities, two of the material consisting of plate-shaped and congruent elements, each on one broadside located tooth-shaped profiling with preferably about the same trapezoidal cross-section of the teeth and tooth gaps are provided and between which are opposite, profiled broadsides of the Elements flat springs are inserted side by side and the opposite broad sides of the elements in a connecting surface are firmly connected.

It has also been suggested from one central foam body to punch out cylindrical cavities and spiral spring elements into these punch holes to insert. This central foam body is on both sides with thinner layers of foam, so-called top layers pasted. On the one hand, this ensures that no essential between the individual spring elements Spring coupling occurs and the spring core in the desired Way point elastic. In a more comfortable Embodiment is between the central foam body and the foamed cover layers a thin fiber or needle fleece glued in as a cushion support.

This is how FR-A-1'593'548 describes a spring core for one Upholstery from a central layer provided with cover layers Foam body with a variety of spring elements, which are used in the foam body, the central Provide a foam body on both sides with a profile is, the elevations and depressions of one another have complementary geometric shape, the Spring elements arranged in the recesses of the profile are.

Unfortunately show this type of combined innerspring after a long time Use unwanted signs of wear on the Top layers, resp. Upholstered straps in the support area of the individual spring elements or it can in the production of such Spring cores a considerable amount of foam residues incurred that can not be used easily.

With today's living and sleeping habits exist alongside the pleasantly felt point elasticity also the Desire for thin and light upholstery. This should not spring back on the one hand and yours on the other Maintain shape in the long term. Unfortunately it shows that with such thin pads with combination spring cores their metallic spiral springs under heavy loads be compressed so that their individual turns collide directly. This leads in particular to the Use of interconnected spring elements (Bonel systems) to unwanted metallic noises.

It is therefore an object of the present invention cost-effective and low-wear upholstery core with good To create point elasticity, which is suitable for use in thin upholstery elements is suitable. In particular, a Combination spring core with a central foam body be created systematically during production generated waste and with which Spring core noiseless and freely dimensionable cushion elements can be produced.

According to the invention, this object is achieved by a spring core solved with the features of claim 1. Here is the central foam body in a special way on both sides profiled, i.e. point the elevations and depressions of the each profile a complementary geometric shape on. In those places where there are deepening opposite are spring elements, preferably metallic Coil springs, used. This particular form of central foam body and the coil springs used also guarantees a precise position Assembly of the spring elements within this foam body, because these spring elements are shaped and dimensioned are that their ends on the elevations of the Fit the foam body profile. In a preferred one Embodiment, the coil springs are biased and can clamped on the elevations of the foam body profile become.

The construction according to the invention means that when Glue the cover layers, respectively. Upholstery carrier, hereinafter also called top layers, on the foam body the ends of the coil springs between these top layers and be held onto the foam body. Such inserted and fixed spiral springs are also worn out intensive and prolonged use accurate and contact-free side by side and can't deal with the facing layers rub. Your vibration behavior can by the Foam body and the top layers in the desired way be dampened. The contact of the individual spiral courses the spiral springs on each other under extreme load or low height is due to a double conical shape Coil springs on the one hand and by the one in the middle Foam part prevented.

According to the invention, the elevations of the foam body profile formed on both sides as parallel ribs. These ribs point to their spaces complementary geometric shape, creating a low-waste Fabrication can be realized and the Have production costs cut. These ribs also work stiffening in their longitudinal direction and allowing it at the same time the spring core in the transverse direction without large To bend effort, as is the case with couches that can be raised Head and / or foot ends is desired. When bending can the padding layer in the spaces of the ribbed Dodge foam body and thus increases flexibility of the entire cushion element transverse to the direction of travel the ribs.

By individually fixing the spring elements in the Gaps between these ribs will also be optimal Point elasticity creates and can be in the spring core easy to assemble, i.e. in desired sizes cut.

Other advantages of this type of low-wear combination spring core are immediately apparent to the person skilled in the art and are not only in the waste-free production method and the free dimensionability to see, but lie especially in the silent mode of operation as well the improved cross ventilation. With conventional combination spring cores can the air in the cavities do not circulate freely and do not escape under load always silent. The construction according to the invention allows good ventilation of the entire cushion element.

It goes without saying that physical properties for the foam body or the top layers used foam in the desired manner by the expert be chosen and the spring strengths respectively. Pen shapes the desired requirements can be adjusted. In particular individual springs can be combined into spring groups be to an individual stress profile to be able to correspond or can be additional upholstery or Spring positions are provided.

Fig. 1

ein Kombinations-Federkern bekannter Art;

Fig. 2

eine bevorzugte Ausführungsform eines erfindungsgemässen Kombinations-Federkerns;

Fig. 3

ein Ausschnitt aus der in Fig, 2 dargestellten bevorzugten Ausführungsform.

The invention will be explained in more detail below with the aid of an exemplary embodiment and with the aid of the figures. It shows:

Fig. 1

a combination spring core of a known type;

Fig. 2

a preferred embodiment of a combination spring core according to the invention;

Fig. 3

a section of the preferred embodiment shown in Fig. 2.

The spring core 1 shown in FIG. 1 has a known type a central foam body 3 on both sides with Cover layers 2 is provided. An elastic adhesive layer 12 ensures the connection between the top layers 2 and the foam body 3. These cover layers 2 can be made from a simple foam layer exist or additionally one Include nonwoven layer. The foam body 3 has cylindrical recesses 6 into which spring elements 4th are used. With a local load on this innerspring are the individual springs through the massive Foam body 3 and through the relatively rigid nonwoven fabric coupled together, i.e. can't really be point elastic Act. Foams are not just synthetic Products but also natural foam rubber or foamed latex in question.

In contrast, Figure 2 shows a central foam body 3, which on both sides with a rib-shaped profile is provided, the elevations 5 and depressions 7 a have complementary geometric shape. In the illustrated The embodiment is the cross section of the rib-shaped Trapezoidal profile and points towards the central part broader base on. It is understood that this is trapezoidal Cross section can also be designed such that the wider base is on the side of the top layers 2. The Spring elements 4 are mounted in the respective recesses 7, i.e. are not from each other by the foam body 3 coupled and ensure good point elasticity. The individual spring elements 4 are the flank course adapted to the profile and point in the illustrated embodiment a biconical shape. To the exact Ensure positioning of the springs within the spring core, protrude the winding ends of the individual spring elements 4 over the elevations 5 and lie on the end faces 11 of these surveys.

The respective cover layers 2 are with the end faces 11 of the Elevations 5 of this profile glued. Through this gluing the spring ends are held in position and can also with extreme upsets or deflections of the entire innerspring do not slip out of their position and touch each other. In addition, the spring elements prevented from the top layers by this fixation to scrub and damage them after prolonged use. The two sides of the foam body 3 parallel ribs running towards each other lead on the one hand to a Stiffening of the entire spring core in the direction of the ribs 5 and at the same time for greater flexibility across this direction. The complementary is essential to the invention geometric shape of the elevations 5 and depressions 7 of the Profile because it is used in the manufacture of this central Foam body 3 no unwanted cutting waste attack. This special geometric design leads in addition to cross ventilation, which is the noiseless Escaping the air facilitates under extreme loads.

Figure 3 shows a section of the preferred embodiment. This has a central foam body 3 with ribs 5, the trapezoidal cross section of which tapers towards the top layer 2. In the complementarily shaped space, a spiral spring 4 is used, the uppermost end of the winding 13 rests on the end face 11 of the profile elevation 5. These spiral springs 4 are preferably preloaded such that they act against the spring force of the foam body ribs 5. It is thereby achieved that the springing behavior inherent in the spring elements is dampened by the elasticity of the foam. The hardness of the springs can be chosen according to requirements and is essentially determined by the thickness of the spring wire. In the preferred embodiments, springs with a wire thickness of 1.4 to 2.6 mm are used. The maximum diameter of these springs is 60mm, but can of course be adapted to the geometry of the foam body. Plastic foams of 20-70 kg / m ³ are preferably used as the foam body. The profiled foam body 3 has, for example, a total height of 10 cm, the central web 8 of which has a thickness of 15 mm. The height of the individual springs 4 is adapted to this overall height of the foam body and varies in the preferred embodiments between 6 cm and 14 cm. The adhesive layer 12 creates a connection between the end faces 11 of the elevations 5 and the cover layer 2, such that the winding end 13 is held in place. In a simple embodiment, these cover layers 2 consist of foam with a thickness of approx. 25 mm, so that the entire spring core can be reduced to a height of 11 cm. The shape of the spring elements 4, which is adapted to the shape of the interspaces, prevents the spring elements 4 from rubbing against and damaging the foam body 3. A significant advantage in the combination of foam with metallic springs is the fact that the elasticity of the plastic foam, which usually diminishes in the longer term, can be maintained through the dimensional stability of the spiral springs.

Due to the independent positioning of the metallic Such a spring core also proves to be springs easy to assemble, i.e. can this around the feathers can be cut around in any way. Through the double conical shape of the spiral springs and the thin foam layer of the foam body in the middle area of the spring elements can turn them under extreme loads do not come to rest on each other.

It is understood that the application differs accordingly shaped spring elements selected and used can be. For example, biconical, cylindrical or barrel-shaped spring elements can be used. As well it lies in the professional ability to group individual feathers to summarize the resilient properties adapt desired load profiles. Understands it is that the specialist instead of the coil springs too Rubber springs or similar elastic elements into consideration would pull. Likewise, the foam body can be made from one Cut into pieces or from several different ones Layers. For easier assembly of the Spring elements can the recesses of the ribbed foam body be slotted in a suitable manner. The Flanks of the individual ribs can be adapted to the spring shape become. It is also in the professional ability, one Adhesive with the desired elasticity for the adhesive layer 12 to choose.

Claims (9)

1. Spring core for a cushion stuffing comprising a central foam element having covering layers, said central foam element having a plurality of spring elements inserted therein, whereby the central foam element (3) is profiled on each side, the elevations (5) and recesses (7) of said profile having a mutually complementary, geometric form, whereby the spring elements (4) are spiral springs which are arranged in the recesses (7) of the profile, characterized in that the ends of the individual spiral springs (4) repose on the elevations (5) of the profile.
2. Spring core according to claim 1, characterized in that said foam element (3) comprises ribs (5,8) on each side which are arranged parallel to each other.
3. Spring core according to claim 2, characterized in that the elevations (5) have a trapezoidal cross-sectional profile.
4. Spring core according to claim 2, characterized in that the elevations (5) have a rectangular cross-sectional profile.
5. Spring core according to one of claims 1 to 4, characterized in that the spring elements (4) are metallic spiral springs.
6. Spring core according to one of claims 1 to 5, characterized in that the cover layers (2) are glued to the front ends (11) of the elevations (5) and that thereby the ends of the individual spiral springs (4) are fixed between these elevations (5) and the cover layers (2).
7. Spring core according to one of claims 1 to 6, characterized in that the spring elements (4) have a biconical form.
8. Spring core according to one of claims 1 to 6, characterized in that the ends of the spring elements (4) have a diameter of 60 mm.
9. Cushion stuffing element having a spring core according to claim 1.

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