FI80842C - PRESS AVSEDD FOER TILLVERKNING AV SKIVOR AV MASSIVT TRAE. - Google Patents

Abstract

1. A method of making a solid wood board (1) by pressing together a plurality of plies (2, 3, 4) of wood strips (5) in a pressing direction extending transversely to the latter, at least one of which forms a surface-layer of a visible surface of the solid wood board (1), characterized in that the surface-layer (2, 4) is compressed transversely of the pressing direction and of the grain of the wood strips (5) forming said surface-layer (2, 4) until the wood strips (5) of the surface-layer (2, 4) arch, that the arching of the wood strips (5) is limited by a stop (6, 7) to prevent breaking out thereof and that then the archings of wood strips (5) are pressed flat with simultaneous supporting of the compressed side edges of the surface-layer (2, 4).

Description

80842 1 Press for the manufacture of solid wood panels Press avsedd för tillverkning av skivor av massivt trä 5

The present invention relates to a press for the production of solid wood panels according to the preamble of claim 1.

10 For a number of uses, in particular in the manufacture of valuable furniture, waxed wooden boards are used instead, which, even after modification, can live heavily, thus leading to rejection, cracking or similar damage, solid wood boards made of several layers of relatively small pieces. puullstoista. These wood strips are cut in the direction of the fibers so that there is a single fiber direction predominant in each layer. The directions of the fibers of the two adjacent layers of wooden slats and thus also of the slats themselves are transverse to each other. These layers are placed in the above-mentioned known presses 20 between two mutually moving spray boards and are pressed together during gluing to form a solid wood board which can be shaped like a waxed wood board but which is not prone to damage in the same way.

25 At least the wooden strips of each surface layer, which form the surface of the solid wood panel, are made of faultless wood, so that after splitting and gluing the surface formed by these wooden strips it cannot be seen that it is not made of a single piece of wood, but of several non-assembled strips. However, after the manufacture and modification of such a wood board, there is a certain shrinkage in the transverse direction of the fibers of these wood slats, which does not crack the solid wood board itself or render the board unusable or dimensionally inaccurate, but results in differences between the individual appear, so that the desired impression of a wooden board of the same piece is no longer achieved.

It is an object of the present invention to further develop the above-mentioned press in that this press or the method used in connection therewith results in a solid wood board in which, even after prolonged use in unfavorable climatic conditions, such as very dry mucus, no separation seams can be observed. between the wooden slats forming the surfaces.

This object is achieved according to the invention on the basis of the characterizing part of claim 1.

In this case, two side pushers are used, which compress the surface layer of the wood board or both surface layers in a direction transverse to the direction of bursting of their fibers and the press board so far that the wood strips of each surface layer are curved. At the same time, the pressing device is adjusted so that the distance between its pressing plates in the rest position is slightly greater than the thickness of the surface layers of the pressing plate. In this way, the wooden strips which curve outwards or inwards under the effect of the lateral impact come tightly against the press plates, so that their further curvature until these wooden strips break is avoided.

After reaching this situation, the side pushers come to their end position and remain there for a short time, after which the press plates are moved to their end position, where they press these curves evenly when they reach their end positions. The press plates remain in the end position until the gluing is completed. The side pushers and press plates are then moved apart, so that the finished solid wood board between them can be removed.

In particular, when the curves of the wooden strips forming the surface layers are pressed evenly by means of press plates, very high forces occur when the contact between the side pushers and the surface layers takes place. The side pusher must therefore be positioned evenly against the side edges of the surface layers and completely cover these to prevent cracking of the wood in the area of the side pushers. The side pusher must therefore preferably be connected to the pressure plates. For the last uniform pressing of the press plates, the necessary

II

According to the invention, the side pushers according to the invention are divided into two jaw parts, each of which adheres to a corresponding surface layer. These jaws move relative to each other in the direction of movement of the press plates so that during the final stage of the pressing operation, when the greatest forces are applied to the surface layers, their side edges retain their gripping contact with that jaw portion. Since the jaws of each side pusher approach each other in the final stage together with the surface layers, damage to the side edges is avoided and a flawless solid wood board is obtained which is compressed transversely to the fiber direction 10 so that no separation seams appear continuously between the individual wood layers. made of one-piece wood panel.

The intermediate layer or layers interposed between the surface layers are preferably offset against each side edge of the surface layers against which the jaws of the side pushers rest in order to avoid disturbing contact of the jaws.

In this connection, it should be emphasized in particular that the invention relates not only to a press according to the invention, but also to a method of manufacturing solid wood panels, the essential part of which comprises compressing 25 in which case the flattening compression of the fermentation point thus formed takes place by means of a constant spray contact.

The jaws can be formed as through strips, the height of which corresponds to the height of each surface layer. However, according to a preferred embodiment of the invention, both jaws of each slide pusher are provided with facing and interlocking guide members, which are preferably formed as opposite grooves or steps extending in the direction of movement of the side pushers. Thanks to this arrangement, the contact surface extends to the height of the side edges of the surface layers along the entire length of the jaws so that they cannot move locally transversely to their direction of movement, thus effectively preventing damage to the sides when applying high temperature compressive forces 4 80842 1. In addition, both jaws have a shoulder opposite these members in the region of their gripping guide members placed at the height of the middle layers of the solid wood panel, which enables the solid wood panel to be made with flawless stepless side edges.

In principle, guide vanes for relative movement, as described, are sufficient to ensure the required movement of both jaws of each side pusher in the direction of the burst pressure 10 of the press plates. However, according to a preferred embodiment of the invention, the two side jaws are hinged together, the pivot axis running parallel to the side jaws. Namely, the press plates are normally placed horizontally, so that the lower press plate can be used as a solid base for the layers of solid wood board. The side pushers 15 are lowered with the upper press plate, whereby the lower jaws of both side work titles enter the pivot position, where they pass smoothly past the solid wood layer layers placed on the lower press plate or the machine table to the lower press plate or the machine table. Thereafter, each lower jaw automatically pivots in connection with the joint downward movement of the upper press plate and the upper jaws of the two side pushers, whereby it always remains at the height of the lower surface layer. In this way, a simple, yet reliable and trouble-free press is formed for suitably manufactured solid wood panels.

25

The invention will be described in more detail by way of example in the following with reference to the accompanying drawings, in which:

Figure 1 shows diagrammatically the layers to be pressed or glued by means of a press according to the invention on a solid wood board;

Figure 2 is a schematic representation of a spray duster according to the invention;

Figure 3 shows a vertical section of a press according to the invention; and 35

Figure 4 shows an end view of an embodiment of the side jaws of a side pusher according to the invention.

Fig. 5 80842 1 Fig. 1 shows diagrammatically and without the correct dimension a solid wood board 1 formed of wood layers 2,3 and 4, each of which is made of parallel wood panels 5. The wood panels 5 of both surface layers 2,4 run parallel, the wood panels 5 of the intermediate layer 3 placed between these layers 2,4 perpendicular to the wood strips 5 of the surface layers 2,4.

In one embodiment of the press according to the invention, the length of the wood strips of the surface layers is 560 cm, the length of the wood strips 5 of the intermediate layer 3 is slightly less than 10 230 cm, the thickness of the wood strips of the surface layers 2.4 is 4.3 mm and the total height of the three layers 2,3 and 4 is 19 mm.

The fibers of the wooden slats 5 run in their longitudinal direction.

Figure 2 schematically shows a pressing operation according to the invention.

The plate assembly according to Fig. 1 is placed on the lower pressing plate or on the machine table 6. The upper pressing plate 7 20 parallel to the lower pressing plate 6 is lowered to an intermediate position where its lower surface is at a distance b from the upper surface of the upper surface layer 2.

In this position, pressed both of the surface layers 2,4 one visible in Figure 2 in the direction of arrow a by means of slvutyöntl-25 systems shown in Figure 3 in greater detail. As shown in the figure, the intermediate layer 3 is moved backward against the under side edges of the surface layers 2,4 of the arrow a in place of compressive pressure, so that the intermediate layer remains in place in the compression carried out.

30 The burst pressure in direction a is increased so long that the wooden straps tend to yield as it curves. This curvature can take place, as shown by the upper surface layer 2 towards the free surface, or also towards the intermediate layer 3 as schematically shown by the lower surface layer 4. It is essential, however, that due to the position of the upper pressing plate 7, the curvature of the individual wooden slats 5 cannot exceed the value b / 2, this value being chosen so that no damage to the individual wooden slats 5 can be caused by their curvature.

6 80842 1 In this situation, the slv edges of the surface layers 2,4 become inelastic and after a certain short setting time the upper pressing plate 7 is lowered completely again to a distance b, whereby the curves of the wooden slats 5 are pressed evenly. In this position shown in Fig. 3, the press remains for a short additional time, after which the press is opened and the finished solid wood board can be removed.

Figure 3 shows a cross-section of a press according to the invention. In this figure, the upper pressing plate 7 is shown in its end position with respect to the lower pressing plate.

On its upper side, the upper pressing plate 7 supports only a schematically shown pressing plate 9 for pressing both sliding pushers 8 in the direction a (Fig. 2).

15

The side pusher 8 is provided with a fixed leaf 10 attached to the upper spray plate 7, which can be moved along the lower surface of the upper spray plate 7 and which must completely cover the edges of the wooden strips 5 of the upper surface layer 2.

20

A downwardly extending extension is formed at the ends outside the pressure plates 6,7 of the upper jaws 10, supporting a rigid hinge shaft 11 extending perpendicular to the plane of Fig. 3 and thus extending in the direction of movement of both the pressure plates 6,7 and the side pusher 8. The lower jaw 12 is articulated. mounted on this hinge shaft 11, with the lower jaw 12 resting on the lower surface of the lower pressure plate? 6 or against the machine table and its height is such that the thickness of the wooden strips 5 of the lower surface layer 4 is not underestimated.

According to a variant, the side pusher 8 can also be lowered at least within certain limits independent of the upper pressing plate 7, so that in the position shown in Fig. 2 a distance b is also formed between the upper jaw 10 and the upper pressing plate 7.

35 In any event, the height of the jaws 10,12 must be chosen so that their contact surface always covers the overall height 2.4 of the surface layers in question.

7,80842 1 As can be seen from the figures, each of the side pushers 8 is able to keep the cuffs of both jaws 10,12 in perfect contact with the respective sliding edges of the upper or lower surface layer 2.4, respectively, in the operating mode shown in both Figure 2 and Figure 3.

5

In Figure 3, both jaws 10,12 are shown schematically with the lowest possible height. In reality, the embodiment according to Fig. 4 is better and shows two jaws 10 ', 12' in the aiming direction, i.e. in the direction α according to Fig. 2. These jaws 10 10 ', 12' then extend at their contact surfaces over the entire height of the free space between the two pressure plates 6,7 in the end position according to Figure 3, the two jaws 10 ', 12' being provided with opposite projections and corresponding grooves which engage each other so that the relative displacement 15 of both jaws 10 ', 12' in their longitudinal direction is prevented. In addition, the formation of a continuous straight seam between the two jaws 10 ', 12' is avoided, which could lead to damage to the intermediate layer 3, the contact surfaces of both jaws 10 ', 12' coming into contact with this intermediate layer at the end of the spraying step.

20 25 30 35

Claims (3)

A press for making solid wood panels by pressing a plurality of layers of wood strips together, these layers forming at least one surface and cover layer of 5 solid wood panels using (a) two press plates parallel to each other and the solid wood panel layers, and 10 (h) a pressing device for transferring from the end position for receiving the solid wood board and placing new layers between the press plates to the press position for pressing the layers together and back, characterized in that it has the following characteristic features: (c) two with each other and a surface layer (2,4) side pushers (8) parallel to the wooden slats, which can be placed between the pressing plates (6,7), 20 (d) each side pusher (8) being formed by two mutually parallel jaws (10, 12), each of which can be placed in contact by means of a support surface against the side edge of each surface layer (2,4), the support surface extending at least to the height of this side edge, 25 (e) both jaws (10, 12) of each side pusher (8) can be moved towards and away from each other, (f) lateral pusher (8) for moving the solid wood board (1) and placing the new layers (2,3,4) from the end position 30 to the spraying position, where the sliding pushers (8) compress the surface layers (2,4) with such force that these surface layers (2) 4) the wood strips (5) curve, and (g) a pressing device for retaining these press plates (6,7) in a position where it limits the curvature of the wood strips (5) of the surface layers (2,4) by a safe distance (b). II 9 80842 1 Claims Press according to Claim 1, characterized in that the two jaws (10 ', 12') of each side member (8) are provided with opposing and engaging guide members (13) for their mutual movement. 5 Press according to Claim 1 or 2, characterized in that the two jaws (10, 12; 10 ', 12') of each side pusher (8) can be pivoted against one another about an axis (11) parallel to them. 10 15 20 25 30 35 10 80842