FI81986B - Timber-sawing process - Google Patents

Abstract

The invention comprises a sawing method, by which the timber's own inner structure is made as far as possible to correspond to the shape of the obtained sawn products without any actual waste timber being formed. According to the invention, this is made possible by a new kind of thread sawing performed in the grain direction of the timber, whereby sawn goods are separated gradually from logs, from within as it were, the radial and annual ring directions of which sawn goods largely coinciding with the direction of the sides of the sawn goods. Since this kind of sawing can be continued step by step to the centre of the logs, the sizes of the logs can be freely chosen. A technical solution of this kind can be realized using quite light devices of small power requirements, including in a large number of special conditions, during production of modern sawn goods, compared with, for example, frame, circular and band saws. The devices for sawing can be constructed in transportable form and, with the aid of this sawing method, a truncated cone can be separated [lacuna] the centremost part of the log for use as a prop. <IMAGE>

Description

81986

METHOD FOR SAWING WOOD

The invention relates to a method for sawing wood, by means of which diverse timber in the direction of the fibrous field of wood can be advantageously removed from wood.

A disadvantage of current sawing methods is that traditionally sawn timber is susceptible to deformation due to changes in humidity conditions due to the fact that current sawing methods cannot effectively take into account the inhomogeneity due to the fibrous structure of the wood. The shrinkage properties of the wood in the tangential direction and in the radial direction differ significantly from each other, e.g. in spruce the ratio of these shrinkages is 2: 1. For many other tree species, such as conifers and deciduous trees, this ratio is 1.7-1.8. As a result, traditionally sawn timber has a high tendency to twist.

The method according to the invention provides a significant improvement in the above-mentioned drawback. The invention is characterized by what is stated in the claims. The main advantage of the invention is that wood in the direction of the fibers can be removed from the wood, the cross-sectional shape of which is freely selectable, and that the wood can be sawn out in a controlled manner both from the outer circumference of the wood and when approaching the center of the wood. In addition, the core of the sawn wood can be separated, for example, into a round blank for further processing.

In the following, the invention will be explained in detail with reference to the accompanying drawings.

Figure 1 shows the sawing of saw grooves in a circular saw. Figure 2 shows the removal of timber with a wire saw.

Figures 3a, 3b, 3c, 3d show different shapes of jet sawn timber.

Figure 1 shows how the sawing of the log (1) is started with a pair of circular saws (2) for sawing parallel sawing slits (3).

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Figure 2 shows how the timber sectors are detached from the logs to be sawn, so that the log is attached from its center to a bearing bracket (6) on an articulated shaft (7) with which the log can be rotated to the desired position. With a wire saw (4) with fastening suction 1 (5), a pair of circular saws saws the wood between the sawn slits off the logs. During sawing, the feed movement can be effected either by rotating the log or by moving the wire saw (4) sideways.

Figure 3a shows an application of triangular strips obtained by radial sawing.

Figure 3b shows a sawn product (9) with a symmetrical annual ring structure.

Figures 3c and 3d show how the sawing of the core part (10) remaining from the sawn logs on the outer circumference can be continued in layers by means of the method according to the invention, whereby the residual part is in the shape of a piece (11) and is suitable for veneer turning.

The invention is not limited to the embodiments described above, but can be modified within the scope of the inventive idea contained in the claims. Timber removal can only be done with a wire saw, saw grooves can be made with a single circular saw and the wood can be supported on its outer circumference during sawing.

It is also possible to add to the above applications the possibility that, with the wire saw 5 of the supports, Fig. 1, after removing the sawing product 9, for example immediately after the first sawing, much heavier and more efficient saw blades can of course be used greater in total value.

Claims (6)

A method for sawing wood, wherein wood parallel to the fibers of the wood (1) is removed from the wood (1) by sawing, characterized in that the wire saw blade (4) is inserted into the wood parallel to the wood (1) through the saw gap (3). made on the surface of the wood (1) to be sawn, and that the removal of the timber takes place essentially by machining a wire saw (4) in the direction of the wood fibers, the machining movement of which is reciprocating or unidirectional. Method according to Claim 1, characterized in that the sawing slot (3) is directed towards the center of the wood. Method according to Claims 1 and 2, characterized in that the sawing slot (3) is made with a wire saw (4). 3,881,986 Method according to Claims 1 and 2, characterized in that the sawing slot (3) is made with a circular saw (2). A method according to claim 1, characterized in that the feed movement of the wire saw takes place by rotating the wood blank around the longitudinal axis of the wood according to the machining ability of the blade. Method according to Claim 5, characterized in that the wood blank is rotated about the center of the annual ring of the wood. 4,81986