AU2003200526B2 - Method and apparatus for profiling a log - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventors: Address for Service: Invention Title: Key Knife, Inc.

STAGER, Bradley, R.

LUECKE, John, S.

DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000 Method and apparatus for profiling a log The following statement is a full description of this invention, including the best method of performing it known to us.

Q:\OPER\ARL\FEB\2614309 44,DOC 17/2/03 METHOD AND APPARLATUS FOR PROFILING A LOG The prcsent invention1 relates to a niethod and apparatuIS for profili ng a log, particularlY Cor cutting a reentrant comner In thc log that cxtcinds alongt tile logu.

To process lo~s into stanidard lumnber, the logs are first slobbcd on onec to four 5idc6. To avoid Nva5c andj. tL)CCL~ ecrs-cto riIuIS 2eeia li round, this processing Inte~ntlonally lca\'es four rounded corneris. Referrin'., first to Fig~ures IA anid I B dcpicting. rcspectivcly, the cross-section of the log bcfoi-e and aftcr being slabbed onl four sides aind then turnring to Fig-ure I C. thc rounded cornitrs arc removed by cutting" in1to the log along its longtudinal Ixis conecspondin- rceentrant comners This squzire s portions of the log. indicated In the FiVL1VC as that arc located between the contours of adjacen-t corncrs so that the portions are configured to he cut into pieces of standard lumiber. Formiing the corners C is typically rcferred to as I"profiling" and an apparatus adaptcd for this purpose is typically referred to as a "Iprofiler." Ail exarnplo of a prior art pro Fler is shown in, Figure 2, First and second knives 2 and 4, which arc idcntical, are disposed on thc circumnfeIrec of a rotatI'ngl disc 6. A slabbed log 8 11L.IVnC an elonglate axis is fed toward the disc along a circumferenitial direction The cuttingl ed~c of the First kn-ilfe is orienlted parallel to the axis of rotation of the disc and the cutting edge of the second knife is or-icnted In a plane of rotation of tne disc. Referring back to FigU re I C, the First knife cuts a first leg of a par-ticular reentrant corner C and the second knife cuts a perpendicular, second lc- "12' of the rectitran-. corner, wherein the legs I I Lind 12 mneet at a rcgion of intersection "c I" of the corner C. It should be understood that the legs "ItI" and "2 ar.- thc visible portions of plana-r surfaces extending along the longitudinal axis of the Another example of a prior art profiler replaces the second knife with a sequence of cuttingc teethi disposed around the periphery of the disc, such as the teeth of a saw blade.

In both of these profilers, the first and second kniv'es are disposed so that thc first knife meets the log at a different time than does thc second knife. Because there is relative movement between the disc and the log, this time difference provides an opportunity for the two cuts to fail to intersect precisely at the same comer region c I and thereby fail to form a clean or smooth corner C. In particular. there often results.

running longitudinally along the comer C, "feathers" or slivers of wood partially but not completely removed from the lou. or other unevenness in the surface txtMurc of the corner. This result is often aggravated further as wear occurs in the apparatus.

Accordingly, there is a need for a method and apparatus for profilinv a log that provides for the formation of smoother surfaces in corners ct thereby and for maintaining this capability despite wear in the apparatus.

One aspect of the present invention provides a method for profiling an article of wood, comprising providing a first knife having a cutting edge, rotating the knife about an 1 5 axis of rotation, orienting the knife so that said cutting edge lies substantially in a plane perpendicular to said axis of rotation, and feeding the article of wood against the knife in a feed direction perpendicular to said axis of rotation so that said cutting edge, at a point of entry to said knife into the article of wood, makes a substantially nonzero angle with respect to the direction of the grain in the article of wood.

2 o Preferably, an abutting relationship of the tips of the knives is maintained against the forces typically encountered by the knives during use. The knives preferably include keyways that mate with corresponding keys in a mounting member for holding the knives.

The keyways and keys substantially prevent the knives from moving in response to the forces.

Therefore, it is a principal object of at least one embodiment of the present invention to provide a novel and improved method for profiling a log or other elongate article.

P:\OPER\Ar\2614309 spec.doc- 1/05/04 -3- It is another object of at least one embodiment of the present invention to provide such a method that provides for the formation of smoother surfaces in corners cut thereby.

It is still another object of at least one embodiment of the present invention to provide such a method that provides for maintaining the aforementioned capability despite wear in the apparatus.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, as set out below.

Figure 1A is a cross-section of a log.

Figure lB is a cross-section of the log of Figure 1A after having been slabbed.

Figure IC is a cross-section of the log of Figure 1B after having been profiled.

Figure 2 is a plan view of a first prior art profiling apparatus.

Figure 3 is a partially exploded view of a profiling apparatus, showing a single rotor and a preferred mounting member.

Figure 4 is a side elevation of the profiling apparatus of Figure 3, taken along a line 4-4 thereof, showing four rotors.

Figure 5 is an exploded view of the preferred mounting member of Figure 3.

Figure 6 is a plan view of a profiling apparatus, shown cutting a log.

Figure 7 is a simplified pictorial view of two knives for use in the profiling apparatus of Figure 6, shown in a first orientation with respect to a direction of travel of the log.

Figure 8 is another simplified pictorial view of the two knives of Figure 7, shown in a second orientation with respect to the direction of travel of the log.

Figure 9 is a simplified pictorial view of two knives of the profiling apparatus of Figure 6, shown in a preferred configuration in the second orientation of Figure 8.

A profiling apparatus 10 is shown in Fi .'Lrcs 3 and 4. The proriling apparatus is particularly adapted for profiling a log; however, it may be cniployed for proilhin,- any elonuate article. Thle tem-n -proilhing" meians fundonicntally to alter tile shape of the article for somic productive purpose.

Referriny back to Figures I DaLnd I C, typically, tis involves altering in elongsate fo1711 Such ;is thle roundcd corner "CrouncF' ol'a slabbed lo,- into ail elongpate, reentrant, square corner This configurcs thle mateil indicatcd Itn Fic-ure I C as which lies between th0 conltours ofne iehboing corners C into an orthorhombic confieuraiton. or "squarcs" the material. It should bef bor1n inind throughlout that .her reentrat shaipes could be Formed, or corners could be 1FJrmled havin- othecr angles \aryin- from 90 degrees. \\'hiere that is dcsirable, and the operation could bc pe rformid onl elongate articles other th:iri logs without decpartinge fromt the principles of the iflveftioll.

Re ferr inrg t o Figure a rotor 12 is provide d \vith a1 desired mnmbr of miounting mnbers 14. suchi as four,. Thec rotor may be disc shaped or it may have somie alitrnative configuration suchi as That shiown. As shown in both Figu1res s3and 4, the rotor rotates about an axis As in Figure 2, a slabbed log 8 hanving iln elongate axis is fed toward the rotor a circumferential dircction wvhich is represented in Figure 4 and wvhich is per-penidicular to thec plane of Fliaore S.

Each mnounrn member 14 Includes two holders 1 6 and I S. Each holder is adapted to clamp ar, associated kifc 17 and 19 to the miountingc. member. The knives may be any cutting imrpleents including, for example, sawV Teeth. The mounting memnber is, In turn, adapted for mounting to the rotor 12. The identifieation of 23 discrete parts such as ihic mrounTting" member and rotor may be sortewhat. arbirar-y since these parts could be combined Into ain integral unit and function identically for purposes of tile presenti invention. Howvever, it is often prcfcrablc to provide these components as individul1 parts That are adapted to be corincctcd together with machine screws or bolts.

2 0 The holders 16 and I S are adapted for clamping thieir re-spective k-nives to the niount~nflC ele-ment and for releasing thle knifle to allow the knife to be rcmnovcd therefrom. Any of a number of prior art holders may be em-ployed. A particularly advaintaueous holder is that described In U.S. Patent No. 5.979,522. wVhich is shaped to Ili knivcs ninrketed by 1Key Knife, Inc., under thec trademiark KEYKNIFE.

Figure 5 prescnits a marc det~ailed \'Icw of a pref-r-red mounting nmmber 14 as shown In Fi-Unre 1. Thle kni\cs 17 and 19 ha3Ve reSPcefVe cu~ttill" edges 20 anld 22.

Thic knife 1 7 is miountcd by the holder 16 to the niountin nicmlbcr 14 so that the cutung edge 20 extenids parallel to 11hC rotational axis of the rotor. The knifc 19 is moun ted byti hIolIder IS to ti t mo LI i g mcmber so ltI tileh cutting cdsc 22 lies In a pianc of' rotation of (lhc rotor'. The: catI111- cdges 20 and 22 arc typically disposed to forM a190 dICgreC anglle teee en for' CLuttim a square coarnerl C.

Refcr-ring particularly' to FI-CUrc 5. the, knives aire pretfcrably dapte:d so that Lback sidc of the knifc 17 abuts a side sur-face 25 of the mf 19 to formn a nitiered comicr. For this pui-posc. the sidec surface 25 of the- knife 19 is Angled obliquely with resptct, to the cutting edge 22, and For cut.ting oppositc corn1er's C. left and right handed versions Of the anle' and. thereforc, the kiif 19 mav be provIicd.

cLing1 edgecs deFine lines comiposcd Ofa lnmber Of points. Cutting action by Cach knife creates rcspcctive surfaces, typically though not necessarily planes, as a resul,1t Of thle cutting edges progressing through the work as a1 result of relative movenrt there betwe'en. Similarly, cutting1 a1ction resuinMg from a particular point on a cutting edge creates a lint, typically though not necessarily siraIht as r rsult of 2 0 the relative movement. The mounting member is configured so that at least one of the points on one of the cutting cdges is proximate at Icast one of the points on thle othecr of the cutting edges. Preferably, these points are end points of the respective cutting edges nd, preferably, these points abut one another, such as shown In Figure 4.

Particularly, where the cutting edges arc brouglht Into proxiate coincidence at thcir end points their tips, It has been found that this coincidence is pr-eferably no more than about I S" for notable mininlization of surface irregularities such as "waviness" and feathcrs, with 1/1G' being a more dcsirable outer limit for comnmercial practice. It has also been found that decreasing the chip size generally pcrmilts a larger separation between thle points for purposes of minimiizing waviness, but the gencration of feathers is not substantcially affected. Neithcr waviness nor the Zgeneration of7 feathers is substanti-ally aff-ected by the sixe of the kiveNIs.

III adIditionI 1o recotnI/ing( that it IS Important to aniwem the knIves in a close Tipto-ttp relaitionship to Improve cLtiNno finish. the present inventors have also rccoqnizc6 the imlportince of providing for ma1inltainling suIch a rcLitionslhip durinig usc of the apparatus. A chipping ki fc istypicaly C]211pcd to a moun,11ting miember by a knife h~older. e.gl.. I bolt -\CjcdinjL thr1ough the k-i fe holder into eithier the mounting member oithe rotor, Dur-Ing UsC Of 111C aIJparatus, the bolt mnay looseni, allowing thc knlife some la1tUid to slip backwardly from thec direcrion 'of rotation. Whecre Two knives that were aIrrangI'ed Ill tip-to-Lp abutting relatOiospslip SIn IIunequ3l aImounts. a gap develops therebctwccn. Moreover-, any gap so fornied may becomie pack-cd wih debris from the 1-tcpackin" catisinu the knives to spreod ftiFtlvr and further aparl from one another durin12 Continued usd.

Corresponding mating features are provided in the kni\'es 1 7 zid 1 9 andL thec mou ntlr, in member 14, to SuhStania-llyV 1ock thc knives linto a selected Position wvith respect theret~o. For manan n abtin relationship of the tIPS oF th le U I ves even 1c Thet c lamipin- Forcc for hold Ing1 thC kilfe eXer-ed by thle holderS 106 and I S to the mounting memiber is reduIced TO 7zero.

Ficure 5 shows a preferred structure- for This purpose. In the precferred striucture, thie knives 17 and 19 each include ii kcyw\ay 15, and the mounting, member t 4 includes cori-esponding keys 3? and 4 that are adapted to Ftt closely the key'ays 15 of the knives.

The kevwmvs and keys 32 and 34 are adapted so that Interiocking the key~ways and the keys prevents movelmentr" of the knlives In a1 direction perpendiculair to their cutting cdges, or in the direction of rotation of thle Mounting member. In the preferred strUCture, the kcy\%an\s arc slots forn-ed In the knives extending paralljel to thle cutting edges of the knIives as shown and described more fully in Carpenter et al., U.S. Patent No. 4,S50'408' incorporate d by reference herein in Its cnitirety.

Providlin- for- lock ina the knlives to thec mounting memiber rather than thec holdcrs 16 and 18 malitais their relaitive positions. The holders. are subject to loosening becausc they are particuilarly aidapted to apply a clantiping force to thec knives which muLst he removable in order to replace the knives.

The closeness of fit between the keys and keyways is allowed to vary depending on the allowable separation of the tips of the knives. Preferably for maintaining a substantially abutting relationship of the tips of the knives, the keys should fit the keyways to a tolerance of less than about 0,015".

Alternatively, other corresponding mating features in the knives and mounting member could be provided to accomplish the result of substantially locking the knives together, as will be immediately appreciated by the person of ordinary skill. For example, other shapes of keys and keyways may be provided, such as shapes, ridges or ribs in either member. As a further example of keyed corresponding mating features, a pin and aperture combination could be provided. As an example of a non-keyed mating feature, a nonremovable or otherwise rigidly attached "backstop" to the knife could be employed. The backstop would be used in conjunction with the corresponding mating feature defined by the back surface of the knife as defined by the direction of rotation of the knife. Corresponding mating features may be keyed or non-keyed according to the principles of the invention.

Preferably, the mounting member 14 is formed of a single piece of metal, to enhance the security with which the relationship of the knives is maintained. However, this is not essential to the advantage provided by the present invention.

Turning to Figure 6, the profiling apparatus 10 is shown in a typical configuration.

The log 8 is shown in elevation as traveling in a direction that is substantially along the longitudinal axis of the log. The grain of the log is defined approximately by a series of concentric cylinders having their axes in the direction The rotor 12 is shown provided with three mounting members 14, and the axis of rotation of the rotor is perpendicular to the direction In cutting the log along its travel direction the knives enter the log at point reach a maximum depth of penetration at point and exit the log at point The inventors have recognized that for cutting clean and sharp corners as shown in Figure IC, it is most advantageous to avoid cutting the wood with either of the cutting edges 20 or 22 parallel to the grain This is to avoid "pulling up" the fibers making up the grain.

As It is dcpictcd in Figu1,re 6, thc knife 17 eNtends Into thc plane of thc paper and, therefore, its cucting edge 20 is always per-pendicular to The grain. Howvever, the angle thc ~if eg 2 akswihrespect to the gain chancs ztlon2- its path from to to This can be appreciated by comnparing Fi2Lures 7 and S, In both Figure 7 and Figure S, the knives 1 7 and 19 arc shown in I con1figuration for cuuting square corners wherein the angle 09 between the edtues 20 and 22 is 90 degrees. Howver, In Figurc 7, the ki\'CS are showvn relative to the log travel direction as they- would appcar at poini: wile Ini Figure S, the knivcs arc shown relative to i s they wVould appear at poinit in Figre 6. At point (Figure both of te eu-in edces 20 and 22 arc perpendicular11 to the traivcl dircction and thLerefoire tpern~endICI.113r to the2 grain.

Howeve\,r. at point (Figure the- cutting edge 22 Is p~ialel to thc grain. This is tin dcs able.

Turning to Figure 9, the present apparatus provides a selected angle ci) between thef cuttim edge 22 and the line defined as being peCrpC1ndicular to thlt Travel directionl and ich axis of ration at poit As best seen In Fi,-uLre 6. the angle ciD is precfe-rably de-terinined by conistrxtcing a radial line exteriding from the tips of the knives 1 7 anid 19 to the center of the rotor the same,- result bcing obtained by projecting. InI a plane pcrpcndicuilar, to the axis of rotation, the lie extending from thc lips of the knives to any point on theC axis of rotation.

An angular vnriation of the angle CiD about the tips of the knives is preferably withinl about 15 degrees. As can be appr-ciated by inspecting Figure 6 and considrn the goal of mninmzing parallelism wvith the gri a. iiscrcrally desirable that thie angle (D greater where the depth of penetration into the log (Figure 6) a S compared to the radius of" the urc Traveled by the tips of [lhe knives, is greater.

The consideration of the angle qi) is substantially indepecndent of the choice of the angle 0. For exanmple, the projections of the cutting edges 20 and 2-2 in the direction of rotation of the miounting mnember 14 that is responsible for The shape of tht- corner "C" (Figure I remain 90 degrees apart regardless of the choice of the angle (D.

IT is to be recognized that, while a panicular method and apparatus for profilling a log has been shown and descrl'bed as preferred, other config urat Ions could be utilized, in P:\OPER\ArI54786-00 SPE.doc-14/02/03 -9addition to configurations already mentioned, without departing from the principles of the invention. Moreover, there is no intention to limit the invention to use in profiling apparatus where there may be other applications involving similar considerations for which the present invention provides similar advantages.

The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention of the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims (4)

1. A method for profiling an article of wood, comprising providing a first knife having a cutting edge, rotating the knife about an axis of rotation, orienting the knife so that said cutting edge lies substantially in a plane perpendicular to said axis of rotation, and feeding the article of wood against the knife in a feed direction perpendicular to said axis of rotation so that said cutting edge, at a point of entry of said knife into the article of wood, makes a substantially nonzero angle with respect to the direction of the grain in the article of wood.

2. The method of claim 1, further comprising providing a second knife and disposing said second knife with respect to said first knife so that respective tips thereof substantially abut one another.

3. The method of claim 1, further comprising providing a second knife and disposing said second knife so that a cutting edge thereof is substantially parallel to said axis of rotation.

4. The method of claim 3, further comprising disposing said second knife with respect to said first knife so that respective tips thereof substantially abut one another. A method for profiling an article of wood, substantially as described with reference to the drawings. DATED this 14th day of February, 2003 Ket Knife, Inc. By DAVIES COLLISON CAVE Patent Attorneys for the Applicant