EP0334834B1 - Method for radially cutting round wood - Google Patents

Abstract

This method produces for wooden constructions new outer-wall mouldings which are manufactured in a simplified, wood-saving manner and which afford substantially improved durability, and weathering protection, and prevent the wood from cracking. Using the hitherto known methods for cutting round wood to form boards and beams, with the subsequent second operation employing separate wood-shaping machines, labour-consuming outer-wall mouldings whose outer faces do not adequately withstand the weathering influences are produced. Using the method for radially cutting round wood which is the subject of the application, the round wood is predominantly radially divided in one operation on a circular-saw machine, and at least two finished, substantially different, new outer-wall mouldings are simultaneously produced thereby, said mouldings affording, due to their hard annual rings cut over their entire surface while upright, at least twice the durability with regard to weathering than hitherto. In addition, the radial-cutting method produces in the new outer-wall mouldings no drying shrinkage and sun cracks and no knotholes, which again contributes to the substantially increased durability. Using only circular-saw cuts, it is possible to produce, in one operation in a circular-saw machine, three substantially different finished outer-wall mouldings. The figures (D, E, F, C) are characteristic of the new radial-cutting method which is the subject of the invention. <IMAGE>

Description

I. State of the art and its deficiency symptoms

So far, the production of bulk sawn timber from logs has been carried out by so-called saw frames with vertically or horizontally reciprocating saw blades or with the all-round band saw blade.

In one step, parallel cut boards or squared timber are obtained as cut raw material. From this raw raw material of the 1st stage of work, in the 2nd or 3rd stage of work, the finishing is done by shaping cut or planing. specially manufactured wood end product.

So far there are at least two local u. Separate processing stages on at least two different processing machines are necessary in order to be able to produce the finished wood product for special purposes.

In addition, there is the disadvantage that the parallel separation of the round wood (with the exception of the proportionally small core separating pieces) on the board cut surfaces between the hard wood annual rings shows the softwood over a wide area and, as a result, the longitudinal fibers become worn and stand out when used. This also results in the qualitatively particularly reduced side goods.

During the drying process, the boards and posts buckle and deform against the wooden core side and thereby lose considerable commercial value and reduce the wood yield for the next processing step. The branches that have not grown together fall through and on thick boards there are surface fissures that promote fungal attack.

II. Contemporary task, in particular for wood recycling on external walls with rain and direct sunlight.

• a) In order to counteract the premature decay of wood due to penetrating moisture and direct sun radiation, the formation of wood cracks and knotholes must be prevented and the hard wood annual rings must be opposed to the weather attack closely and over the whole area. The proportion of the softwood surface is reduced to a minimum.
• b) The rain and windproof design of the parting joints is essential.
• c) It is crucial that from the cylindrical, debarked logs in one operation and in a processing machine in a continuous processing run, with the highest timber yield, without any noteworthy wood waste, at least two profiled outer wall moldings for different requirements arise, which do not deform during the subsequent natural or artificial drying and also meet the wood conservation benefits of a) and b).

Such a woodcut process is the leap in technical progress with proven inventiveness.

III. Mode of operation of the circular log radial cutting method registered here

This radial cutting process fulfills the contemporary task listed under II. In the following way.

The debarked, cylindrical round wood rolls (1), assumed to be 2 m long, are pushed longitudinally axially through a feed pipe by continuous pressure and constant feed speed of the circular saw and leave after the cutting process as radially separated, core-free and. finished external wall molded parts in a discharge pipe the machining circular saw.

This creates two or three or four substantially different, finished outer wall molded parts in one operation and in a circular saw machine at the same time. The variety of molded parts is an advantage for the market, because they are a novelty on the market.

Compared to the previous multiple work steps, the objective single work step is the substantial reduction in production costs.

It is also crucial that the cut surfaces of all 4 new exterior wall molded parts have the cut, tight, hard wooden annual rings all over.

In this way, they achieve at least twice the duration of the existing wall formwork.

The absence of drying u. Sun cracked by the radial wood fiber separation.

Cutting process according to figure (A)

The extended motor shafts (2, 3) of the two drive motors (4, 5) are at an angle of 30 degrees to one another, more or less,
The drive motors (4, 5) are arranged at such a distance in the direction of the longitudinal log axis that the circular saw blades (6,7) which cut radially to the center of the wood cannot touch with their tooth tips.

The tangential cutting saw blade (8) also rotates on the circular saw shaft (2) and the saw blades (9, 10) rotate on the circular saw shaft (3) and cut flat spots on the round timber (1).

The radial cuts according to Figure (A) result in two finished products at the same time, namely the core-free, self-supporting full block shape shown in Figure (B) and the core-free half block shape shown in Figure (C) for upright construction.

Cutting process according to figure (D)

The radial cutting saw blade (11) and the tangential cutting saw blades (8, 13, 14) rotate on the motor shaft (2). The saw blade (13) creates a radially standing conical round cut.

The radial cutting saw blade (12) and the tangential cutting blades (9, 10, 15) rotate on the motor shaft (3).

The circular saw radial cuts according to figure (D) result in three finished products at the same time, namely the core-free wedge shingle shape shown in figure (E) with sealing overlap and the core-free wedge shingle shape (F) shown in figure (F) with groove and additionally that in figure (C) Core-free semi-block shape shown (C).

All four outer wall formwork profiles (B, C, E, F,) that can only be produced with the radial cutting machine shown here by changing the circular saw blades, have in common that they are all cut radially to the log core and therefore none on the exposed wooden surface on the weather side No shrinkage from the sun and no branches through the branches and no drying deformations.

Practice has shown that the durability of the wooden outer walls made with it has almost been doubled compared to the previously common designs without radial cuts and that the visual image has been improved for many years by largely preventing weathering of the wooden surface.

The changing round wood diameter of cheaper small wood from 8 cm to 16 cm in diameter can be processed by simply changing the circular saw blades, without any noteworthy wood waste, in the required thicknesses of the outer wall profiles (B, C, E, F,) and thus optimally used.

Claims (1)

1. Method for radially cutting round wood for the production of outer wall parts to protect against hail, wind and sun, characterized by the fact that the round wood (1) is fed continuously over the longitudinal axis through a circular saw and thereby over two radial cutting circular saw blades (6, 7) and three tangential cutting circular saw blades (8, 9, 10), which are operated by two drive engines (4, 5) the shafts (2, 3) of which are set at 30°, more or less opposite a centre plane, with the round wood thus being cut in one operation into the form of a finished full block separated from the core (B) and at the same time into the form of a finished half block separated from the core (C), whereby an alternative offers in addition to the circular saw blades (8, 9, 10), a passage via the radial cutting saw blades (11, 12) and the tangential cutting circular saw blades (13, 14, 15) which simultaneously cut the round wood (1) into the form of a finished wedged shingle separated from the core (E) and a finished wedged shingle with a groove separated from the core (F) whereby the outer wall parts (C, E, F) display hard annual rings, cut vertically, over the whole surface, thus giving increased resistance to wood fissures and weathering.

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