Method and an apparatus for producing wood wool

[57] ABSTRACT

Thin sheets are sliced from a block of wood by means of a continually moving planing tool. As each sheet is separated from the block it is deposited on a slowly moving conveyor. On this conveyor the sheets are superimposed in staggered relationship like fish scales and form a steady stream conveyed to a wool cutting station where a cutter cuts the wood wool from the superimposed sheets transversely thereto.

Claims, 9 Drawing Figures

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PATENWR21 1972 3,650,480

SHEET 1 OF 4

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PATENTEDMAR21 1972

3,650,480

SHEET 2 OF 4

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PATENTE0MAR21 1972

3,650,480

SHEET 3 OF 4

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PATENTEDMAR21 Γ972

3,650,480

SHEET U OF 4

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VUI

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3,650,480

METHOD AND AN APPARATUS FOR PRODUCING WOODWOOL

FIG. 8 is an elevation of the planing tool shown in FIG. 6, partly in section taken along the plane VIII—VIII of FIG. 7 and

FIG. 9 is a side view similar to that of FIG. 1 of a modified embodiment differing from that shown in FIG. 1 by the wool cutter which, in this embodiment, is formed by a reciprocating blade.

A preferred embodiment of the novel apparatus for producing wood wool is shown in FIG. 1. The frame 1 of this apparatus is illustrated diagrammatically only and need not be described in detail. The wood wool produced by the apparatus is indicated at 3. It consists of long curly strips or ribbons of wool produced by shredding starting material in form of substantially cylindrical blocks 5 of wood cut to a predetermined length. These blocks 5 are placed one above the other in parallel relationship so as to form a pile. Suitable holding means are provided for holding the pile and for presenting it to one side of a planing tool. In the embodiment shown such holdmg means are formed by a pair of parallel sets of feed rolgate substantially parallel rollers mounted one above the other. Each roller is provided with longitudinal circumferential teeth capable of engaging an end face of the pile of blocks 5 as shown in FIG. 3. Each roller is journaled in bearings (not shown) mounted in frame 1 for horizontal displacement towards and away from the pile of blocks and suitable springs are provided to urge the bearings towards the pile to thereby ensure a firm grip of the pile of blocks between the two sets of rollers.

Successive thin sheets of wood are continually sliced from the bottom of the pile by the planing tool 11.

For this purpose suitable feeding means are provided for producing a relative feed motion between the holding means 7 and 9 and the tool 11. In the embodiment illustrated in FIG. 1 the feeding means include sprockets 13 fixed to the rollers 7 and 9 and cooperatively connected by chains with a sprocket wheel driven by an electric motor 15 mounted on frame 1.

As the holding and feeding means briefly described hereinabove are well known in the art, a detailed description thereof is deemed dispensable herewith. It may be mentioned, however, that the bearings supporting the feed rollers are preferably adjustable so as to permit the distance of the set 7 from set 9 to be changed in accordance with the length of the blocks 5. A guiding element 8 can be provided for avoiding jamming of the block rest under the lowermost feed roller 7.

In lieu of feed rollers other suitable feeding means may be provided, such as endless chains or other conveying means.

An important feature of the present invention is the use of a 50 particular type of planing tool, to wit of a substantially diskshaped rotary planing tool provided with at least one cutting edge, but preferably with three cutting edges 25, FIG. 7, angularly spaced by 120°. Each cutting edge 25 is provided on a blade 17,19 or 21, respectively, each disposed within an aper55 ture 23 provided in the disk. The blades 17, 19 and 21 are so mounted that their cutting edge 25 projects above the top surface of the disk, as will appear from FIG. 7. Each blade is fixed to the disk by suitable connecting means including a screw 27. Suitable means are preferably provided, such as slots accom— j --------blades.

Forwardly in the direction of rotation of the tool the recess 23 is confined by an insert 29 forming part of the disk. Its top surface 31 is slightly inclined so as to somewhat project above

The front wall of the recess 23 formed by the insert 29 and the rear wall of the recess are inclined with respect to the axis of rotation of the disk and may slightly converge upwardly, whereas the blade provided with the cutting edge 25 has subfile inclined rear wall of the recess 23 and being firmly pressed thereon by the fixing means including the screw 27. The front wall or lower wall of the blade, however, is spaced from the front wall of the recess 23 so as to confine a slot therewith 75 adapted to receive a slice 41 of wood cut from the bottom of

The present invention relates to a method and an apparatus for producing wood wool.

BACKGROUND AND OBJECTS

In a prior apparatus for producing wood wool disclosed in the German Pat. No. 35,166 a planing tool formed by a smooth blade is mounted on a reciprocating slide and adjacent to the blade a plurality of grooving knives are mounted.

In a similar prior apparatus for producing wood wool shown and described in the U.S. Pat. No. 3,087,521 a multiplicity of circular cutting blades has been substituted for the grooving blades and is so mounted as to follow the smooth blade of the planing tool. Each of the thin sheets successively sliced by the planing tool from a block of wood is divided by the circular cutting blades into a multiplicity of narrow ribbons or strips constituting the wood wool.

® --------e ——J u-v υγ a pan ui parallel seis OI teed rolMoreover, a match cutting apparatus has been shown and lers 7 and 9, each set comprising a plu rality of horizontal elon15 described in U.S. Pat. No. 3,266,538 in which a rotary cutter provided with a plurality of circumferentially distributed cutting blades extending substantially parallel to the axis of rotation serves the purpose of successively cutting narrow strips from the leading edge of a sheet of wood, such strips being used for producing matches.

It is the object of the present invention to provide a method and an apparatus for producing wood wool which excel by a continuous operation of high efficiency resulting in the production of wood wool of a high quality, the narrow ribbons forming the wool having clean cut faces.

It is a further object of the present invention to provide an improved method and apparatus for producing wood wool in which the undesirable production of dust is practically eliminated.

Finally it is an object of the present invention to provide an apparatus of the character indicated which is of simple and rugged design and reliable in operation, the cutting elements and the means for guiding the moving elements of the apparatus being subject to a minimum of wear.

Further objects of my invention will appear from a detailed description of a number of embodiments of my invention described hereinafter with reference to the drawings. It is to be understood, however, that the present invention is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

THE INVENTION

In the drawings

FIG. 1 is a diagrammatic side view of an apparatus for producing wood wool embodying the invention, the individual ribbons constituting the wool being cut by means of a rotary cutter of the drum type;

FIG. 2 is a plan view drawn on an enlarged scale of the rotary disk-shaped planing tool of the apparatus shown in FIG. 1 and of the elements disposed thereabove;

FIG. 3 is an elevation of the upper portion of the apparatus

III—III of FIG. 2, illustrating feed rollers for feeding the wooden blocks, the planing tool and a conveyor for conveying the sheet sliced from said blocks;

FIG. 4 is a partial plan view of another embodiment of the ___________ invention illustrating the conveyor extending from the planing 65 the plane top surface of the disk, tool to the wool cutting station, the wool cutting tool in said station being formed by a rotary of the disk type cutter;

FIG. 5 is a side view of the structure shown in FIG. 4;

^FIG. 6 is a plan view of a modification of the planing tool nozzles serving the purpose of depositing and holding down the sheets sliced from the block on the conveyor;

FIG. 7 is a partial sectional view of the planing tool shown in FIG. 6, the section being taken along the plane VII—VII in FIG. 6, the view being on an enlarged scale;

« Ο 1 J · ^*v*viuvij JJlvVIUvLlj oUVll uu oiULb dVwOITl —

HI III¹ f Pir ,-1.^{2, part y a sectl0n taken alon}8^the P^{lane 60 m}°dating the screws, to afford adjustment of the individual , . _₇ - _ ,,. . — ¹— ° — w.ui me cuiLing euee zo nas suoshown m FIG. 2 such planing tool being provided with air 70 stantially parallel rear and front walls, the rear wall abutting nozzles serving the nurnnse nf dp.nncitino __j________u r.i --. .. - ®

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4 the lowermost block 5 and to guide such slice or sheet downwardly through the recess 23 and past the bottom of the disk-shaped tool as shown in FIG. 3. The disk is fixed to or integral with a vertical shaft journaled in bearings fixed to the frame 1 of the apparatus. This shaft is geared to the pinion 5 shaft of an electric motor 35 by a suitable transmission diagrammatically indicated in FIG. 1 at 33. During the rotation of the planing tool 11, its blades 17, 19 and 21 will slice successive sheets of substantially equal thickness from the bottom of the pile of wooden blocks 5, the motor 15 being operated at ‘θ such speed as to ensure that the lowermost block 5 is urged towards the top surface of the disk-shaped tool.

The gap formed between the rear edge of top surface 31 of the insert 29 and the cutting edge 25 located above such rear edge has a width corresponding to the desired thickness of the ¹⁵slices or sheets of wood. The rear face of the blade adjoining the edge 25 is slightly relieved so as to provide a suitable relief angle.

The sheets 41 of wood successively sliced from the lowermost block 5 by the cutting blades 17, 19 and 21 and downwardly discharged from the recesses 23 of the diskshaped planing tool drop into the space disposed below the planing tool 11. Conveyor means including an endless conveyor 37 are disposed below the bottom of the tool 11. The 25 conveyor 37 has a supporting surface which is movable past the tool 11 for receiving the sheets for deposition in superimposed staggered relationship like fish scales. The conveyor 37 extends from a point closely below the planing tool 11 to a wool cutting station shown at the right in FIG. 1. Suitable 30 means 39 are disposed above the conveyor 37 for holding down the sheets deposited thereon in staggered relationship. In the embodiment illustrated in FIG. 1 such holding means are formed by an endless belt movable in a path extending parallel to the conveyor 37. The conveyor 37 also is preferably 35 formed formed by an endless belt.

In order to ensure that the thin sheets 41 of wood sliced successively from the pile of blocks 5 are properly deposited on the conveyor 7, when they follow each other rapidly, air nozzles may be provided on the planing tool 11 so as to direct air 40 jets in the sheet-depositing direction upon each sheet sliced off from the block 5. In the embodiment illustrated in FIG. 1-3 and 6-8 a plurality of such air nozzles formed by air ducts 43, 45 is provided on the bottom of the disk of tool 11 and on the lower front surface of each blade 17, 19 or 21, respective- ⁴⁵ly, confining the recess 23. The jets issuing from such nozzles are indicated by the arrows 47 in FIG. 3. Compressed air is temporarily supplied to the nozzles 43, 45 by a rotary distributor 49 diagrammatically shown in FIG. 8, whenever the nozzles pass across the conveyor 37. The nozzles 45 may be rearwardly inclined with respect to the rotary cutting motion of the tool 11 as shown in FIG. 7. Experience has shown, however, that even without such air nozzles 43, 45 the apparatus will ensure proper deposition of the sheets. Even when the ap- $$ paratus is operated at a very high speed, each sheet issued from the recess 23 will be pressed downwardly upon the conveyor by the following sheet discharged from the following recess 23.

The endless conveyor 37 and the endless belt 39 are carried by driven rollers and idle rollers journaled in stationary bearings (not shown) carried by frame 1. The driven rollers are driven in timed relationship to the frequency of the sheets issuing from the planing tool, the timed relationship being so chosen that the sheets will be deposited on the conveyor 37 in 65 staggered overlapping relationship like fish scales. In FIG. 9 a transmission 40 is diagrammatically indicated which cooperatively connects the shaft of the planing tool 11 with a driving belt driving one of the rollers carrying the conveyor 37. This transmission 40 is so designed as to provide for the required 70 timing of the speed of conveyor 37 to the rotary speed of the planing tool 11.

In FIG. 1 the staggered relationship of the sheets 41 deposited on the conveyor 37 is clearly shown. In this embodiment the conveyor is inclined downwardly towards the wool 75 cutting station, the angle of inclination being such that the staggered sheets assume a substantially horizontal position on the conveyor.

Each block 5 of wood represents a section cut from a log in which the fibers extend parallel to the axis thereof. Preferably the holding means 7 and 9 are so disposed relative to the axis of the disk-shaped planing tool 11 as to hold the blocks with their fibers extending substantially tangentially to the rotary motion of the planing tool. Therefore, the cutting edges 29 of the planing tool will cut through the wood substantially lengthwise of the fibers. This results in a clean cut avoiding production of dust. The axis of the belt-driven roller of the conveyor 37 extends transversely to the feed rollers 7 and 9. As a result, the direction of travel of the conveyor 37 is parallel to the feed roller 7, 9 and transversely to the fibers of the sheets. In other words, the steady stream of overlapping sheets transported by the conveyor 37 towards the wool cutting station flows in a direction at right angles to the wood fibers. This is important for the operation performed at the wool cutting station as will appear from the description thereof hereinafter.

If desired, suitable means engaging and accurately aligning the superimposed staggered sheets may be provided below the conveyor 37 as shown in FIGS. 4 and 5. The conveyor 37 may be formed by a plurality of parallel endless belts mounted on the supporting rollers including roller 69 in spaced relationship. A pair of fingers 51 is mounted for pivotal motion about an axis extending horizontally below the conveyor 37 transversely to the belts thereof. This axis performs an orbitary motion about a horizontal stationary axis. For this purpose a driving mechanism 55 is provided. Each finger 51 has a horizontal arm connected to a crank forming part of the mechanism 55. As a result, the top end of each finger 51 performs a motion along an oval path causing the finger to emerge above the supporting plane of the conveyor through a gap between the belts to thereby engage the rear edge of a sheet deposited thereon and to push the sheet on the conveyor in downward direction a slight distance thereby aligning it accurately. In the course of its oval motion each finger 51 after having engaged a sheet is retracted downwardly so as to avoid undesirable interference with the sheets. In FIG. 4 one of the sheets 41 is diagrammatically indicated by broken lines showing engagement of this sheet by the pair of fingers 51, 53. The steady stream of sheets transported by the conveyor 37 with reference to FIG. 4 to the left towards the wool cutting station shown at the left of FIG. 4 is partly omitted in FIG. 4 so as to expose the conveyor 37 to full view.

As the apparatus for producing and conveying a steady stream of superimposed sheets in staggered relationship towards the wool cutting station has been explained, various embodiments of this station will now be described.

In FIG. 1 a rotary wool cutter 58 of the drum type is mounted for rotation about a horizontal axis extending substantially parallel to the axes of the rollers carrying the conveyor 37 and the belt 39. The rotary wool cutting tool 58 has a plurality of circumferentially distributed cutting edges extending substantially parallel to the axis of rotation of this tool. The rotary body provided with such cutting edges is carried by a horizontal shaft journaled in bearings mounted on frame 1, preferably in an adjustable position. The axis of this shaft is disposed slightly above the level of a blade 63 forming a stationary cutting edge cooperating with the cutting edges of the rotary cutter 58. This blade 63 is carried by a block 65 (FIG. 5) mounted on the stationary frame 1 which supports the conveyor 37 and the top of the blade 63 is so located as to slidingly receive the lowermost sheet of the steady stream of sheets flowing to the wool cutting station. Suitable means not shown are provided to impart rotation to the cutter 58 causing its cutting edges to successively cut through the superimposed sheets supported by blade 63, the cut extending downwardly transversely to the direction of travel effected by the conveyor and, therefore, parallel to the fibers of the wood. This again results in a clean cut in which no dust will be produced. The rotary speed of the cutter 58 is so correlated to the speed of

3,650,480 operation of the conveyor 37 that each of the cutting edges of cutter 58 cuts a narrow strip or ribbon from each of the superimposed sheets so as to result in wool of the desired quality. The strips or ribbons drop downwardly into a chute as indicated at 3.

The embodiment shown in FIG. 4 differs from that illustrated in FIGS. 1-3 by the tool mounted at the wool cutting station. In FIG. 4 this tool is illustrated as a substantially diskshaped tool 57 similar to the planing tool. 11. The tool 57 has at least one blade inserted in the disk and forming a cutting edge cooperating with the stationary blade 63. The cutting edge similar to edge 25 in FIG. 7 projects from the front plane of the disk a distance corresponding to the desired width of the strips or ribbons of wood cut from the sheets. The relief angle must be at least so large as to avoid interference of the tool with the conveyor motion of the sheets to be shredded.

In FIG. 9 a third embodiment of the invention is illustrated in which the tool provided at the wool cutting station is of the type comprising a vertical cutting blade, means mounted on the frame for guiding such cutting blade for up and down motion and a crank-driving mechanism 61 operated by an electric motor and adapted to impart a vertical up and down motion to the blade 59. The cutting edge provided by the bottom edge of such blade cooperates with a stationary cutting blade similar to blade 63. If desired, the means for actuating blade 59 and the means for guiding such blade may be so designed as to impart a horizontal component of motion to the blade extending in the conveyor direction.

If desired, the endless conveyor 37 may be provided with longitudinally extending parallel ribs or ridges supporting the steady stream of sheets and the end member 65 supporting the blade 63 may be equipped with a comblike element disposed adjacent to and above the roller 69 having prongs engaging between such ribs or ridges.

In the embodiment shown in FIG. 5 the shaft carrying the disk-shaped tool 57 may be mounted in stationary bearings, the axis of said shaft extending substantially parallel to the longitudinal direction of the conveyor 37. If desired, the bearing may be so adjustable as to tilt the disk-shaped tool 57 about an axis extending parallel to the axis of roller 69. By changing the adjustment of the bearing the disk-shaped tool 57 may be brought into any position located between the position shown in FIG. 5 by dotted lines and the position shown in FIG. 5 by full lines. Moreover, an additional adjustment of the bearing may be provided to turn the tool 57 about an axis extending through the stationary blade 63 at right angles thereto and at right angles to the axis of the tool. This adjustment permits to so position the tool 57 as to cut exactly parallel to the fibers of the wood. Experience has shown, however, that this adjustment may be dispensed with provided that the blocks 5 are properly cut so as to ensure that the fibers of the block 5 extend exactly parallel to the conveyor roller axis.

In the embodiments described hereinabove the rotary axis of the planing tool 11 is disposed substantially vertically, the feed rollers 7,9 being disposed above the tool 11 and the conveyor means being disposed below said tool. Where the planing tool is disposed in this fashion, the cutting direction of the wool cutting tool 57, 58 or 59 is substantially vertical. The wood wool may be conveyed from the chute 3 by a conveyor 71 to a magazine.

The operation of the apparatus described hereinabove is as follows:

After the motors 15 and 35 and a motor (not shown) operating the wool cutting tool 57, 58 or 59 have been started, the blocks 5 are inserted between the two sets 7 and 9 of feed rollers. As soon as the lowermost block 5 engages the planing tool 11, the blades 17, 19 and 21 of the planing tool will successively slice thin sheets from the bottom of the lowermost block 5. These sheets may have the size of an ordinary sheet of letter paper. The transmission 33 may impart about 1,000 revolutions per minute to the planing tool 11 resulting in the slicing of 50 sheets per second from the lowermost block. The transmission 40, FIG. 9, constitutes means cooperatively connected to the conveyor 37 and to the planing tool 11 for operating the conveyor 37 at a speed which is so correlated to the rotary speed of the planing tool 11 that the distance through which the conveyor 37 travels during the period of 5 slicing a sheet from the block is a small fraction of the average length of the sheet.

During the rotation of the planing tool 11 the inclined faces 31 of the inserts 29 will lift the lowermost block somewhat about the top surface of the disk of tool 11 thus reducing the ¹⁰ friction between the block and the tool. The speed of operation of the feed rollers 7,9 is so chosen in relation to the rotary speed of the planing tool and the number of the cutting edges thereof that the slices will have the desired thickness. This . _ thickness will determine the width of the wool strips or wool ribbons.

As shown in FIG. 3 the slices issuing from the recesses 23 of the rotary tool 11 will drop successively upon the supporting surface of the conveyor and are conveyed by the same in a 2q steady stream towards the wool cutting station. The conveyor direction is indicated in FIG. 2 by the arrows A.

The sheets dropping upon the conveyor 37 rapidly and successively will overlap each other in staggered relationship. As a result the sheets will form an acute angle with the supporting 25 face of the conveyor. The means 39 for holding the sheets is adjusted in conformity with the thickness of the steady stream of sheets flowing towards the wool cutting station.

When the sheets pass across the stationary cutting blade 63, they will enter the path of the wool cutting blades 57,58 or 59, 30 respectively. Each of these blades will cut through the superimposed sheets thus continually cutting wood wool from the leading edges of the sheets.

The width of the strips or ribbons cut in this manner and constituting the wool depends on the speed of operation of the 35 conveyor 37 and on the number of wool cutting operations per time unit. This number again depends on the rotary speed of the cutter 57 or 58 and on the number of cutting blades carried thereby.

From the above it will be readily understood that the 40 method and the apparatus described will attain the objects of the invention. In the prior art a multiplicity of grooving knives or rotary cutter blades are operative simultaneously to split the sheets or slices of wood into a multiplicity of strips or ribbons constituting the wool. In the novel method and apparatus ⁴⁵ described hereinabove, however, two smooth blades are operative at any time, one blade slicing successive sheets of wood from the block and the other blade at the wool cutting station cutting wood wool from the leading edges of the su₅0 perimposed sheets. The deposition of the sheets in superimposed staggered relationship on the conveyor permits a continuous operation at a very high speed. As in the prior art each sheet is split in its lengthwise direction into a plurality of strips or ribbons by grooving knives or cutter blades, a much smaller 55 number of strips will be produced than is possible with the present invention where a stack of superimposed sheets is cut at the wool cutting station simultaneously. The length of the substantially vertical cutting path being substantially shorter than the length of the individual sheets. While the sheets may 60 have a length of 20 inches for instance, the length of the vertical cutting path of the wool cutting blade may be but 2 inches.

The use of rotary tools, such as tools 11 and 58, offers the advantage of a high cutting speed resulting in a high output of the apparatus, particularly where the rotary tool is equipped 65 with a plurality of cutting edges. The prior method of simultaneously splitting each sheet into a plurality of parallel strips or ribbons by rotary cutting blades or grooving knives requires a much higher power consumption than the operation of the two cutting tools, to wit the planing cutting tool and the wool 70 cutting tool used in the novel method and apparatus.

The division or separation of each sheet into a multiplicity of strips or ribbons lengthwise of the fibers according to the prior art resulted in an undesirable interference of the rotary cutter blades with the fibers where the fibers did not extend 75 exactly in parallel relationship. Such interference resulted in

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Ί nonlinear cutting faces and undesirable vibrations and in the production of dust. As distinguished from this prior art the novel method and operation results in smooth cutting faces without production of any dust.

In the prior art a considerable pressure must be exerted between the sheet and the rotary cutter blades splitting the sheet into a plurality of strips or ribbons. This required a high power consumption and was liable to generate undesirable heat and dust. The same applies to the use of a reciprocating planing tool equipped with grooving knives. As compared with this prior art the novel apparatus has a much lower power consumption. Moreover, the rotary cutters used in the novel apparatus can be easily journaled by antifriction bearings as distinguished from reciprocating cutting slides as used in the prior art requiring complicated guides involving undesirable lost motion, a difficult dissipation of heat, heat expansion, complicated lubrication and the like. As large reciprocating masses are avoided in the novel apparatus, a simple frame of low weight may be used and the sheets may be sliced from the blocks at a very high speed. This is true even where the blocks ²θ have a spiral growth and have branches rendering the use of a reciprocating cutting tool difficult. Owing to the high uniform cutting speed of the rotary tools used in the novel apparatus, smooth faces will be obtained even where the wood is fed by automatic means.

Finally it should be noted that the inventive concept of continually cutting wood wool fibers from a continuous stream of wood sheets superimposed in staggered relationship like fish scales can be reduced to practice also with other apparatuses than described in connection with the foregoing embodiments. Thus the direction of movement of the sheets emerging from the planing tool 11 can be in the direction of the fibers also rather than transversely thereto. In any case, however, the wool producing cut through the superimposed sheets is parallel to the fibers within the wood sheets.