EP0549526B1 - Slat made of solid wood - Google Patents

Abstract

A slat made of layers of solid wood (11, 12, 13) for sitting and lying furniture has at least one, but at most four glued joints (8a, 8b) which run approximately perpendicular to that side surface (5) which has the greatest extent and connects the individual layers of solid wood to one another. In the individual layers of solid wood, the annual rings are inclined towards the side surface in rift or semi-rift cut. <IMAGE>

Description

The invention relates to a spring plate.

Known spring slats of this type usually have a multi-reverberation of laminated wood slats with glue layers running horizontally to the surface of the slat. Such a spring plate is e.g. described in CH patent 504 860. This construction, as well as the gluing in of plastic parts, improves the spring force and durability of the slats and reduces the risk of breakage of the slats.

Also known from French patent application No. 2,582,980 is a lamella which has a large number of glue layers running perpendicular to the lamella surface. These slats are made from plywood technology and some are also made with glued-in plastics.

There are under-bed constructions in which the slats - in contrast to the so-called "flex" constructions - have a relatively small distance from one another. Slats glued horizontally or laminated vertically from plywood are unsuitable for such underblankets, since they cannot absorb the condensation moisture that arises between the slat and the mattress, which leads to gray spots and mold growth below the mattress leads. This disadvantage is particularly serious if - as is common today - plastic decorations are also glued to the surface of the slat. For this reason, slats made of solid wood are used in the above-mentioned under-bed constructions.

• 1. Sie sind in der Herstellung relativ teuer, da nur absolut fehlerfreies Rohmaterial geeignet ist (besonders bei Konstruktionen, wo die Lamellendicke unter 10 mm beträgt).
  Eine weitere Verteuerung erfolgt dadurch, dass für die Herstellung auf dem Markt normalerweise nicht erhältliche Seitenware-Bretter über 30 mm Dicke benötigt werden, die durch den Baumkanten-Verschnitt den Verlust (neben der teureren Materialbeschaffung) noch zusätzlich vergrössern.
• 2. Der zweite Nachteil besteht darin, dass die Lamellen nach dem Aufschneiden aus den rohen Brettern durch die freiwerdende Holzspannung in der Längsrichtung oft krumm werden, was den Ausschuss erhöht und wiederum zu einer Verteuerung führt.
• 3. Zum Dritten ist die Federspannung der Lamelle, welche wiederum vor allem bei den Konstruktionen mit Lamellen unter 10 mm Dicke ausschlaggebend ist, je nach Holzpartie Schwankungen unterworfen, was die regelmässige Qualität der hergestellten Unterbetten beeinträchtigt.

These known spring blades have three major disadvantages:

• 1. They are relatively expensive to manufacture because only absolutely flawless raw material is suitable (especially for constructions where the lamella thickness is less than 10 mm).
  A further increase in price is caused by the fact that side goods boards over 30 mm thick, which are normally not available on the market, are required, which additionally increase the loss (in addition to the more expensive material procurement) due to the tree edge cutting.
• 2. The second disadvantage is that the slats often become crooked in the longitudinal direction after cutting from the raw boards due to the wood tension being released, which increases the scrap and in turn leads to an increase in price.
• 3. Thirdly, the spring tension of the lamella, which in turn is particularly important in the case of constructions with lamellae less than 10 mm thick, is subject to fluctuations depending on the wood section, which impairs the regular quality of the underbeds produced.

The object of the present invention is to create a spring plate and a method for its production which do not have these disadvantages and which are also simple and inexpensive.

This object is achieved with a spring lamella as characterized in claim 1.

The method for producing spring lamellae consists in that solid wood layers with tree rings are used, which run on the front side and extend at least in regions approximately tangentially to their side surfaces (tangential cut) with the greatest extent, that at least two, preferably a plurality of such solid wood layers over their side surfaces are glued together and that the glued solid wood layers are cut transversely to the tree rings into spring lamellas in such a way that their solid wood layers have an end face rift to half rift cut. This results in spring lamellae with layers of solid wood, in which the spring lamella preferably has a plurality of glues, by means of which the solid wood layers are connected lengthwise with an end-to-end rift to half-rift cut.

Further features of the invention are the subject of the dependent claims.

• Figur 1, 2 und 3 zeigen einen Schnitt durch je eine Federlamelle.
• Figur 4 und 5 zeigen je einen Schnitt durch einen Baumstamm.
• Figur 6, 7 und 8 zeigen je ein Zwischenprodukt aus dem Herstellverfahren.
• Figur 9 zeigt eine erfindungsgemässe Federlamelle.
• Figur 10 zeigt eine weitere Ausführung einer Federlamelle.
• Figur 11 zeigt ein weiteres Zwischenprodukt.
• Figur 12 bis 14 zeigen je eine weitere Ausführung einer Federlamelle.

The invention, its advantages and the manufacturing process are described in more detail below with reference to FIGS. 1-14:

• Figures 1, 2 and 3 show a section through a spring plate.
• Figures 4 and 5 each show a section through a tree trunk.
• Figures 6, 7 and 8 each show an intermediate product from the manufacturing process.
• Figure 9 shows a spring plate according to the invention.
• Figure 10 shows a further embodiment of a spring plate.
• Figure 11 shows another intermediate.
• Figures 12 to 14 each show a further embodiment of a spring plate.

Figure 1 shows a section through a spring lamella 1 according to the prior art, which consists of solid wood layers 2a, 2b, 2c, etc., which are connected by glue layers 3a, 3b, 3c, etc. In addition, a decor 4 is also glued on here. The solid wood layers 2 are arranged parallel to a side surface 5, which is the surface of the spring lamella with the greatest extension or which serves to absorb a load.

2 shows a section through a further spring lamella according to the state of the art with glue layers 6a, 6b, 6c etc. which are perpendicular to the side surface 5. With this type of construction, the penetration of the glue into the pores of the height in the large number of glue layers, the vapor diffusibility of the spring lamella is also severely hampered.

3 shows a section through a spring lamella 7 according to the invention in a preferred embodiment with 2 vertical glues 8a and 8b, which here connect three different sections or solid wood layers 11, 12, 13 to one another. In all solid wood layers, tree rings are shown as they occur with rift or semi-rift cuts, ie. the tree rings are mostly more or less perpendicular to the direction of the greatest extent of the individual solid wood layers or are generally inclined up to 45 degrees, which is then referred to as the semi-rift. In section 12, for example, these are annual rings 9a, 9b, 9c etc. which enclose an angle with the side surface 5 or with the gluing 8a, 8b, as is customary for a semi-rifle cut. An angle 10 is preferably at least 40 degrees. A broken line 14 is drawn in as a comparison value, which includes an angle 10 with the side surface 5. The drawn angle 10 is, for example, 45 degrees. The same applies to annual rings 15 and 16 of sections 13 and 11. It can also be seen here that annual rings 9 and 15 of adjacent sections 12 and 13 do not run parallel, but rather run to one another or diverge. The same applies to the annual rings 9 and 16 of the adjacent sections 12 and 11.

The manufacturing method for spring lamellae according to FIG. 3 is to be described with the aid of FIGS. 4 to 8 described below.

Figures 4 and 5 show incision techniques on the logs to produce so-called side boards. The log or tree trunk 17 is sawn or cut so that boards or layers are formed in the following manner. A first series of parallel cuts results in layers 18 to 25. A second series of parallel cuts, but which are approximately perpendicular to the cuts of the first series, result in layers 26 to 34. What remains is a core piece 35. When cutting or sawing as in Figure 5 is shown, the log 36 is rotated 90 degrees after each cut. For example, layers 37 to 55 are created in succession in the order of the digits and a core piece 56 remains.

In this way, boards or layers are created, as an example is shown in FIG. 6. These boards or layers are cut in a tangential cut or are referred to as side goods. A tree ring 57 can be seen therein, for example. The side surface 5 already known from FIG. 1 runs approximately tangentially to the tree ring 57. At least two such layers 58 are then glued. In this way, for example, a blank 59 is produced as shown in FIG. 7. This consists of three layers 60, 61 and 62, which are connected by glue layers 63 and 64. The individual layers are preferably connected in such a way that the annual rings are concave and / or convex to one another. This is shown as representative of most tree rings for tree rings 65 and 66, which are convex, and 67 and 68, which are concave. The blank 59 is thus composed of boards in a tangential cut.

FIG. 8 shows a further step in the production process that takes place on the blank 59. By means of cuts 69, 70, 71 etc., which take place at intervals 72, 73 and are preferably carried out with a so-called thin-cut creel spring lamellae 74 according to the invention, as one of them is also shown again in FIG. 9. The cuts 69 and 70 are made approximately perpendicular to the gluing or glue layers 63 and 64 in the blank 59.
The spring lamella, as shown in FIG. 9, is obtained by folding it in the direction of an arrow 76. It can already be used in this way. Your side surfaces 5 are then rough sawn, ie not treated or refined. The side surfaces 5 can also be planed or ground and the small side surfaces 75 can be rounded off, so that a spring lamella is created, as shown in FIG. 3. Such spring blades preferably have a thickness of 4 to 12 mm and a width of 20 to 40 mm. In FIG. 9 it can also be seen that annual rings 88 in the end face 91 run approximately as in a rift cut or radial cut.

Further embodiments of the invention are described below which have further advantageous properties. In order, for example, to be able to use biological glue such as casein for gluing 8a and 8b (FIG. 3) without disadvantages, it is advisable to provide layers 77 and 78 made of a further material between sections 11, 12 and 13, as shown in FIG 10 is shown. These layers 77, 78, which can consist, for example, of so-called Fournier wood, of a textile insert, of a woven or braided material or of another material not mentioned here, have the property of quickly absorbing the biological glue in a hardwood compared to the corresponding process, if it is applied to it and then gradually and relatively slowly going to the neighboring wood over a longer period of time. The glue only gets into the wood of the sections 11, 12 and 13 of the spring lamella as quickly as they are able to absorb this glue. The layers of the other material thus act like a temporary glue store. These layers of a further material preferably have a thickness of 0.5 mm to 4 mm and are to be used in particular if if so-called hardwood such as ash or maple is intended as the wood for the spring lamellas in order to produce spring lamellas with a higher load-bearing capacity If the layers mentioned consist of Fournier wood, then they are preferably made of so-called peeled veneer and thus form a uniform layer that is approximately parallel to the tree trunk the tree rings runs. The layers are preferably integrated completely into the glue layers 62 and 63 in the blank 59 as shown in FIG. 7 in the sense of the method already described. This can also be seen in FIG. 11, in which such layers made of a further material are provided here, for example, as softwood layers 79 and 80 between layers 60, 61 and 62.

In order to make the spring blades 74 according to the invention as permeable as possible for condensation, it is also possible to make bores, holes or slots in the spring blades. Such slots 87 are arranged, for example, as shown in FIG. 14, in the spring lamellae 74 in such a way that they connect a support surface 83 for a mattress to a free underside 84 and thus open a path to the outside for the moisture escaping from the mattress. In order not to reduce the strength or load-bearing capacity of such spring lamellae, however, such slots 87 or bores 81 and 82, as shown in FIG. 12, are preferably provided in the layers of the further material, which is particularly advantageous in the case of softwood layers.

Bores, slots and the like should be provided in particular in the central part 90 of the slats, as shown in FIGS. 13 and 14. In this central part, the body of a person lying on the bed is mostly on, and accordingly, most of the moisture that is generated must be removed in this area.

FIG. 13 also shows a spring lamella according to the invention with layers 77 and 78 made of softwood and bores 81, 82 and 86 arranged therein in a top view. Since these bores are last made in the finished lamella, for example by punching, their diameter can be both smaller and larger than the thickness of the layers 77, 78. In the latter case, the bores also engage, for example, in the hardwood of the spring lamella.

• 1. Die Atmungsfähigkeit (Dampfdiffusionsfähigkeit) der Lamelle bleibt im Gegensatz zu konventionell verleimten Lamellen voll erhalten.
• 2. Durch den Einschnitt von dünnen Seitenwarebrettern kann der Rohverschnitt erheblich gemindert werden Ebenso wird der Aufwand für die Holztrocknung kleiner. Die Seitenwarebretter oder das Rohmaterial kann in einer Dicke beschafft werden, wie sie auf dem Markt als Normware preiswert erhältlich ist.
• 3. Durch die vorzugsweise dreiteilige Lamelle werden kleinere Holzfehler (nicht paralleler Jahrringverlauf, Aeste) überbrückt und damit der Ausschuss weiter vermindert.
• 4. Die Verleimung führt zu einem Ausgleich der Holzspannung nach dem Aufspalten (Fig.8) aus dem Rohling, d.h. der Ausschuss durch krumme Lamellen wird erheblich vermindert.
• 5. Weiter werden durch diese Ausführung Federspannungsdifferenzen minimiert und somit ein qualitativ ausgeglicheneres Endprodukt erzeugt.
• 6. Der Jahrringverlauf von mindestens 40 Grad bezogen auf die Lamellenoberfläche führt zu einer Verbesserung der Federkraft der Lamelle, führt auch zum Vermeiden eines Schüsselns der Lamellenoberfläche sowie zu einer weiteren Verbesserung der Atmungsfähigkeit (Dampfdiffusionsfähigkeit) der Lamelle.

The spring blades produced in this way have the following advantages in particular:

• 1. In contrast to conventionally glued lamellas, the lamella's breathability (vapor diffusibility) is fully preserved.
• 2. By cutting thin side goods boards, the raw waste can be significantly reduced. The effort for drying wood is also reduced. The side goods boards or the raw material can be procured in a thickness that is inexpensively available as standard goods on the market.
• 3. Due to the preferably three-part lamella, minor wood defects (non-parallel tree ring, branches) are bridged and the rejects are further reduced.
• 4. The gluing leads to an equalization of the wood tension after splitting (Fig. 8) from the blank, ie the rejects from crooked lamellas are considerably reduced.
• 5. Furthermore, this design minimizes spring tension differences and thus produces a qualitatively more balanced end product.
• 6. The tree ring course of at least 40 degrees in relation to the lamella surface leads to an improvement in the spring force of the lamella, also leads to avoiding bowling of the lamella surface and to a further improvement in the breathability (vapor diffusibility) of the lamella.

Claims (18)

1. Spring blade, characterized by solid wood layers (11, 12, 13) which, based on an end face (91), have a full or semi comb grained cut and which are joined together lengthwise by glue layers (8a, 8b).
2. Spring blade according to claim 1, characterized in that the glue layer (8a, 8b) runs substantially perpendicular to a lateral face (5) with the greatest extension.
3. Spring blade according to claim 1, characterized in that it has at least one and a maximum of four glue layers (8a, 8b) for two or a maximum of five solid wood layers.
4. Spring blade according to claims 1 or 2, characterized in that the lateral face (5) of the spring blades (7) is left in the state obtained from the sawing process.
5. Spring blade according to claims 1 to 4, characterized in that its thickness is 4 to 12 mm.
6. Spring blade according to one of the claims 1 to 4, characterized in that its width is 20 to 40 mm.
7. Spring blade according to claim 1, characterized in that the annual rings are inclined in the semi comb grained out by at least 40°.
8. Process for the production of spring blades, characterized in that use is made of solid wood layers (58) with annual rings (57), which run in the frontal direction and at least zonally extend approximately tangentially to their lateral faces (5) (tangential cut) with the greatest extension, that at least two and preferably several such solid wood layers (60, 61, 62) are glued together over their lateral faces (5) and that the glued solid wood layers (60, 61, 62) are out transversely to the annual rings to give spring blades (74) in such a way that their solid wood layers have a frontal full or semi comb grained cut.
9. Process according to claim 8, characterized in that the glued solid wood layers are directly cut by sawing with a frame saw to spring blades, without subsequent planing.
10. Process according to claim 8, characterized in that the glued solid wood layers are cut at intervals corresponding to the desired spring blade thickness.
11. Process according to claim 8, characterized in that three solid wood layers (60, 61, 62) are glued together.
12. Spring blade according to claim 1, characterized in that the glue layers (8a, 8b) have layers (77, 78) of a further material.
13. Spring blade according to claim 12, characterized in that the layers of the further material have a thickness of 0.5 to 4 mm.
14. Spring blade according to claim 1, characterized in that there are bores (86) and slits (87) interconnecting the lateral faces (5) with the greatest extension.
15. Spring blade according to claim 12 and 14, characterized in that the bores (86) and slits (87) are provided in the layers (77, 78).
16. Spring blade according to claim 12, characterized in that the glue layers have casein and that as a further material for the layer veneer is used.
17. Process according to claim 8, characterized in that the spring blades (74) are provided with bores (86), which interconnect the lateral faces (5) with the greatest extension.
18. Process according to claim 8, characterized in that the solid wood layers (60, 61, 62) are glued together via layers (79, 80) made from a material acting as a glue reservoir.

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