US3059676A - Method of flaking wood and rotary tunnel flaker therefor - Google Patents

Description

R- D. KISER Oct. 23, 1962 3,059,676 METHOD OF FLAKING WOOD AND ROTARY TUNNEL FLAKER THEREFOR 2 Sheets-Sheet 1 Filed April 6, 1959 v INVENTOR Hz iy:

'Richa'rd D. Ifi'ser R. D. KI SER Oct. 23, 1962' METHOD OF FLAKING woon AND ROTARY TUNNEL FLAKER THEREFOR Filed April 6, 1959 2 Sheets-Sheet 2 INVENTOR Rickard-D. 'lfz'a'er ATTORNEY 3,059,676 Patented Oct. 23, 1962 velopment Co. Inc., Tacoma, Wash, a corporation of Washington Filed Apr. 6, 1959, Ser. No. 804,205 6 Claims. (Cl. 144230) This invention relates to a method of flaking wood and to a rotary tunnel flaker therefor.

In the manufacture of wood flakeboard, wood logs or billets first are reduced to flakes by cutting them across the grain. The flakes then are mixed with a thermosetting resin and size, formed into a felt and consolidated into the desired thickness and density in a hot press.

In the foregoing sequence, it is important to provide wood flakers which will operate rapidly, smoothly, and efliciently so as to produce a large volume of flakes at minimum cost and at maximum production rate. In addition, it'is essential that the flakes produced be of substantially uniform thickness, have reasonably sharply defined side edges, and be free from sticks and slivers. Any substantial irregularity in flake dimensions obviously will be reflected in a corresponding irregularity in the properties of the finished board.

This problem is particularly acute in view of the fact that in the usual fiaker the flakes pass as they are formed to gullets located ahead of the knife. This requires making a reverse bend around a sharp corner which, in turn, induces breakage of the flakes.

Accordingly it is the general object of the present invention to provide a rotary, cross-grain, wood flaker which will produce uniform flakes at a high production rate even when the wood being processed is frangible and easily broken, as in the case of cedar.

It is another important object of the present invention to provide a flaker of the indicated class which is capable of precision cutting over long operating periods, but which is easily disassembled and assembled as necessary for servicing and knife sharpening.

In the drawings: I

FIG. 1 is a fragmentary plan view of the herein described flaker;

FIG. 2 is a fragmentary sectional view taken along line 22 of FIG. 1; and

FIGS. 3 and 4 are exploded perspective views of the upper and lower cutter knife assemblies, respectively, in the rotor of FIGS. 1 and 2.

Generally stated, the herein-described method of flaking Wood comprises severing flakes from a piece of wood with a knife, and guiding the flakes across the leading face of the knife and around the base thereof to a discharge station behind the knife, thereby avoiding reverse curling of the flakes and minimizing breakage thereof.

The apparatus by which the foregoing method is accomplished broadly comprises a rotor, a knife mounted on the rotor, gib means securing the knife in cutting position, and a passageway through the rotor positioned and dimensioned to pass a flake cut by the knife along the leading face and around the base thereof to a discharge station behind the same.

Considering the foregoing in greater detail and with particular reference to the drawings:

The flaker of our invention comprises a forged steel, cylindrical rotor provided with shaft 12. The rotor may be of substantial size, for example, from 2 to 3 feet long and from 18 to 36 inches in diameter.

A plurality of circumferentially spaced, parallel, longitudinal gibways 14, which preferably are wedge-shaped in section, are planed out of the rotor. They communicate with knifeways 16 which, in the embodiment illustrated, extend inwardly beyond the gibways and may be formed in the same operation.

Deep pockets or gullets 18 having a pronounced radius are milled out of the rotor periphery at longitudinally spaced intervals along each knifeway, intercepting the knifeway and gibway.

Wedge-shaped gibs 20, preferably formed in short sections for ease of handlingbut shown for simplicity in FIGS. 3 and 4 as extending the full length of the rotor, are seated in each of the gibways. The gibs are formed at spaced intervals with transverse, cutaway portions or passageways 22. These register with gullets 18. Also, the gibs are drilled and tapped at intervals to receive screws 24 bearing against the bottoms of the gibways in the manner indicated in FIG. 2.

Filling or insert blocks 26 may be provided opposite the gib sections receiving the screws to provide continuity of rotor surface. Cutaway portions in the blocks register with the cutaway portions in the gibs to provide continuity of passageways 22 inwardly from the rotor surface.

Knives 30 are seated in knifeways 16. Each knife may comprise a flat bar substantially co-dimensional with the gib. Its outer surface is formed with projecting knife edge sections 32 alternating with recessed, non-cutting sections 34. The base is cut away at spaced intervals registering with the spaced gullets 18 with a radius as indicated at 36 to provide a smooth, continuous passageway for flakes from the front leading side of the knife inwardly along passageway 22 and around the radius 36 to the gullet on the trailing side of the knife.

:In assembling the flaker the gibs and knives are inserted in the gibways and knifeways, respectively, spanning the gullets 18, and the desired knife adjustment secured. Screws 24 then are tightened down, thus drawing the gibs and insert blocks outwardly and wedging the knives in position.

Wood is fed to the rotor across a bedplate, not illustrated, and preferably in a crossgrain direction. The staggered cutting sections of the knives thereupon cut flakes which are guided inwardly along passageways 22 ahead of the knives and across their front faces, thence around the passageways forwed in part by cutaway portions 36 at the bases of the knives, and into gullets 18 on the trailing side of the knives. This movement of the flakes is afforded because they are much thinner than the passageways (FIG. 2). They are stored there pending centrifugal discharge from the apparatus upon continued rotation of the rotor.

In this manner the flakes are cleanly severed from the woody matrix and preserved with a minimum of breakage. As a result, a uniform flake product is produced which may be used to great advantage in the production of flakeboard of uniform properties.

It is to be understood that the form of our invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of our invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. The method of flaking wood which comprises severing flakes from a piece of wood with a rotary knife, and guiding the flakes across the leading face of the knife and around the base thereof to a discharge station behind the knife, thereby avoiding reverse curling of the flakes and minimizing fracturing the same.

2. The method of flaking wood which comprises crosscutting a piece of wood with a rotary knife having a knife edge and a base, the knife edge being maintained substan- 3 tially parallel to the wood grain, thereby severing crosscut flakes from the wood, and guiding the flakes across the leading face of the knife and around the base thereof to a discharge station behind the knife, thereby avoiding reverse curling of the flakes and minimizing the fracturing thereof in a direction along the grain.

3. A rotary flaker comprising a rotor, a knife having a knife edge and a base mounted on the rotor, and gib means securing the knife in cutting position, the rotor being provided with a passageway therethrough positioned and dimensioned to pass a flake cut by the knife along the leading face and around the base thereof to a discharge station behind the knife.

4. A rotary flaker comprising a rotor having in its peripheral surface a plurality of spaced, parallel, longitudinal, intercommunicating gibways and knifeways, a plurality of gib-knife assemblies seated one in each of the gibways and knifeways and each comprising a gib dimensioned to seat in the gibway ahead of the knife and provided with spaced transverse passageways, a knife having projecting cutting sections alternating with recessed noncutting sections seated in the knifeway with the cutting sections aligned with and opposite the passageways which accordingly lead across the front face of the knife and around the base thereof, gullet means in the rotor behind the knife communicating with the passageways in the gib, and means for securing the gib-knife assembly in the rotor.

5. The flaker of claim 4 wherein a continuous gullet is provided through the trailing portion of the gib, around the base of the knife and through the rotor behind the knife, thereby providing a way for passage of the flakes along the leading face and around the base of the knife.

6. A rotary flaker comprising a rotor, and a knife mounted on the rotor and having a knife edge and a base, the rotor being provided with an inwardly extending gullet which is traversed by the knife to provide a passageway which extends continuously from the rotor surface inward along the leading face of the blade and thence around the base of the blade to the rotor surface on the trailing side of the blade.

References Cited in the file of this patent UNITED STATES PATENTS 332,797 Hagerty Dec. 22, 1885 960,526 Erlandsen June 7, 1910 2,477,153 Succop July 26, 1949 2,598,933 Nevin June 3, 1952 2,660,242 Lane Nov. 24, 1953 2,710,635 Alexander June 14, 1955 2,739,627 Vohringer Mar. 27, 1956 2,822,839 Frodermann Feb. 11, 1958 2,836,206 Gaskell May 27, 1958 FOREIGN PATENTS 1,033,888 Germany July 10, 1958 179,088 Australia July 10, 1954 181,596 Switzerland Apr. 16, 1936 269,389 Germany Jan. 20, 1914 802,953 Germany Feb. 26, 1951 1,042,167 France June 3, 1953

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