Woodworking – Slivering machine
Patent
1997-02-18
1998-11-03
Bray, W. Donald
Woodworking
Slivering machine
144 42, 144186, 144176, 1442486, 144373, B27C 112
Patent
active
058295003
DESCRIPTION:
BRIEF SUMMARY
The invention relates to an apparatus for producing sideways curved woodwool fibres, with a flat rotatable disc, in the surface of which is provided at least one knife assembly comprising a thickness knife which projects slightly above the surface of the disc and which has a cutting edge extending substantially radially and further comprising width knives positioned, as seen in the direction of rotation of said disc, ahead of said thickness knife and having a cutting edge extending substantially tangentially, whereas the apparatus further comprises at least one feeding device for feeding the disc with wood blocks to be cut up into fibres.
Nowadays straight woodwool fibres are produced on a large scale. Woodwool comprising straight fibres is extremely fit for the production of woodwool cement boards for constructive purposes, such as self-supporting insulating roof boards. Because the fibres are cut along the full length, optimally in parallel with the grain of the wood, these fibres and woodwool cement boards made thereof maximally withstand tensile and compressive forces.
In practice straight woodwool fibres are almost exclusively planed using planing machines having a reciprocating carriage, in which knives are mounted and which is driven by a crank mechanism. One major disadvantage of these known machines is that generally these operate with only one cutting knife for each wood feeding location and, due to the large mass of carriage and crank mechanism to be reciprocated, can only make a limited amount of movements each minute, thus having a negative impact on the cutting speed and therefore the production capacity. Further, due to the low cutting speed and inevitable play between the carriage and the carriage guiding, the thickness of the produced fibres is irregular, whereas the surfaces of the fibres are not smooth, especially when the width of the fibres is determined by scraping, ploughing or carving rather than by cutting.
An example of such a planing machine having a reciprocating carriage is described in U.S. Pat. No. 2,605,793.
Further apparatuses are known (among others German patent 1,921,867) having cutting knives mounted in a rotating disc, with which straight woodwool fibres can be produced with large capacity.
However, applications exist at which straight woodwool fibres are less appropriate, for example when manufacturing acoustic ceiling panels to be mounted visibly. Now almost no demands exist in respect of the bending and tensile strength of the boards, however from an acoustic point of view an open structure, and from an aesthetic point of view a curved surface structure are preferred. From an aesthetic point of view all fibres should disengage each other entirely and should individually have a regular thickness and width. Further the fibres should be free of hairs and frills, meaning that the thickness and width of the individual fibres has to be determined with high speed by sharp knives rather than by other means employing carving, scraping, ploughing or ripping. It is to be understood, that disengaging frills may form lumps together with cement powder which is used in the boards, said lumps having a negative influence on the acoustic and aesthetical performance of the boards. Further all fibres should have a uniform thickness and width, wherein it is essentially that the thickness of the fibres, often only being 0,2 until 0,4 mm, is cut precisely in parallel to the grain of the wood.
In the light of the above one has tried already in the past to produce sideways curved woodwool fibres. The advantage of such sideways curved woodwool fibres is that they allow the manufacture of aesthetically appealing ceiling panels and the like having an open and curved structure. The curved shape of the fibres almost fully excludes that in the plates fibres are positioned on line alongside and on top of each other, as may happen with straight fibres. As a result panels produced of such sideways curved woodwool fibres obtain an aesthetically appealing uniform curved open structure providing a high
REFERENCES:
patent: 2130457 (1938-09-01), Fickett et al.
patent: 3000412 (1961-09-01), Jaschke
patent: 3517713 (1970-06-01), Filippo et al.
patent: 4148345 (1979-04-01), Rogers
Bau-und Forschungsgellschaft Thermoform AG
Bray W. Donald
LandOfFree
Apparatus for producing sideways curved woodwool fibres does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for producing sideways curved woodwool fibres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for producing sideways curved woodwool fibres will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-680561