AU2003200528C1 - 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:\OPERARL\FEB\2614311 44.DOC- 14/2/03 METHO0D AND APPARATUS FOR PROFILING A LOG The prcseint inv'encion relates to a miethod and apparatus for profiling a log, pirticularly for cutting a reentrant corner in the log that extends along the log.

To process logs intjo standard lumiber, the logs arc first slabbed-on one to four sikcs. To avoid wastc aind. bccause Mhe cross-scction orthic beL is generall% round, this processing intentionally icaves four rounded corncrs, Refe-ing first to Figures I A an d 1 B depicting. rcspecti vcly, the cross-section of tile log before and after bcing slabbed oil four sides and then turning t6 Figure I C, tile rounded corners arc reniovcd by cuttinmit telg ln itniudinal axis corrcspondin- reentrant corners "C.

This squares portions of the log. indicated in the Figurc as that are located bctwveei thle contours of adjacent corners so that the portions are configured to be cut into pieces of standard lumber. Forrming the corners C is typically referred to as .profiling" and an apparatus adaptcd for this purpose is typically referrcd to as a An example of a prior art profiler is shown in Figure 2. First and second kiiNves 21 and 4, which arc identical, are disposed on the circumference of a rotating disc 6. A slabbed log 8 ha%-ina anl clongare axis is fed toward the disc along a circumferential direction Thle cutting ed-c of the first knife is oriented parallel to the axis of rotation of the disc and the cutting edgc of the second knife is oriented in a plane of rotation of the disc.- Referring back to Figure I C, the first knife cuts a first le- "I I of a particular reentrant corner C and tile second knife cuts a perpendicular, second leg "12" of the reentrant corner, wvherein the legs 11 and 12 mecet at a region of intersection "cl" of the corner C. It should be understood that tile legs "it" and "12" are the visible portions of planar surfaccs extending along the longitudinal axis of thle log.

Another cxample o f a prior art profiler replaces the second knife with a sequence of cutting teeth disposed around the periphery of the disc, such as the teeth of a saw blade.

P:AOPER\SAS\ n-Jun 01.614311 Ipa d.I13 4/I6

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-2- In both of these profilers, the first and second knives are disposed so that the first knife 00 meets the log at a different time than does the second knife. Because there is relative movement between the disc and the log, this time difference provides an opportunity for the 00 two cuts to fail to intersect precisely at the same corner region c I and thereby fail to form a t 5 clean or smooth corner C. In particular, there often results, running longitudinally along the corner C, "feathers" or slivers of wood partially but not completely removed from the log or C€ other unevenness in the surface texture 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 profiling a log that provides for the formation of smoother surfaces in corners cut thereby and for maintaining this capability despite wear in the apparatus.

The present invention provides a knife for use in a wood profiling apparatus, said knife being mounted for rotation about an axis in said profiling apparatus, said knife including first and second sides which meet to define a cutting edge, and a third side immediately adjacent the cutting edge and the first and second sides, said third side intersecting one of said first and second sides to define another edge intersecting said cutting edge and lying in the same plane as the cutting edge, wherein the cutting edge is at an angle with respect to said third side that differs substantially from 900, and wherein the third side is perpendicular to the plane.

The present invention provides a knife for use in a wood profiling apparatus, said knife being mounted for rotation about an axis in said profiling apparatus, said knife including first and second sides which meet to define a cutting edge, and a third side immediately adjacent the cutting edge and the first and second sides, wherein the cutting edge is at an angle with respect to said third side that differs substantially from 900.

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.

In another advantageous feature of the invention, the cutting edge of at least one of the knives is angled to avoid cutting the log parallel to the grain, to further improve the surface finish in profiling the log.

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

P:\OPER\Arl\2614311 caims.do-13/07/04 -3- It is another object of one embodiment of the present invention to provide a knife for such a method and apparatus that provides for the formation of smoother surfaces in corners cut thereby.

It is still another object of one embodiment the present invention to provide a knife for such a method and apparatus 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 1C 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.

4 A profiling apparatus 10 is shown in Fi-urcs 3% and 4. Tilc profiling apparatus is partLicularly adapted for profiling a log; however, it may be cniploycd for profiling any elon-ate article. The ten'n"proiling" means fundamentally to alter tile shape of thle article for sonie productive purpose.

Referring back to Figures IlB and I C, typically, this involves altering an elongate fornn such its the rounded corner "Cround" of a slabbed lot, into all elongate, reentrant, square corner This configures tile material indicated ini Figure I C as which lies between the contours of neighIboring corners C into an orthorhomrbic confiouration. or "squ'arcs" the material. It should be bornec in mind throughout that other reentrant shapes could be formiled, or comers could be formied having other angles varying from 90 degrees, where that is desirabkc and thle -operation could bc performed onl elongate articles other than logs without departing from tile principles 'of the invention.

Referring to Fig'Urc 31 a rotor 12 is provided with a desired numnbcr of mounting members 14, such as four, The rotor may be disc sha~ped or it may have somnicrnative configuration such as that shown. As shown in both Figures 3 and 4, the rotor rotates about zn axis As in Figure 2, a stabbed log 8 having an elongrate axis is fed toward thc rotor along a circumferential direction which is represented in Figure 4 and which is perpendicular to the plane of Figure Each mountintt member 14 includes two holders 16 and IS. Each holder is adapted to clamip an associated knifc 17 and 19 to the mounting member. The knives mnay be any Cutting Implemnents including, for example, saw teeth. The Mounting member is, in turn. adapted for mounting to the rotor 12. The identification of discrete parts such as 11hC Mounting member and rotor may be somewhat arbitrary since these panis could be combined into an integral uinit and function identically for purposes of the present invention. Howvever, it is often prcfcrablc to provide these components as individual parts that are adapted to be connccted together w~ith machine screws or bolts.

3 0 The holders 16 and I S are adapted for clamping theirrespccivC knives to the mounting element and for releasing thle knife to allow thc knife to be rcrnov.cd therefrom. Any of a number of prior art holders may b.e employed. A particularly P:\AOPER\SASUanJun .06\2614311 Ispa d.3 1103/06 advantageous holder is that described in U.S. Patent No. 5,979,522, which is shaped to fit 00 knives marketed by Key Knife, Inc., under the trademark KEYKNIFE.

Figure 5 presents a more detailed view of a preferred mounting member 14 as 00 shown in Figure 3. The knives 17 and 19 have respective cutting edges 20 and 22. The t 5 knife 17 is mounted by the holder 16 to the mounting member 14 so that the cutting edge extends parallel to the rotational axis of the rotor. The knife 19 is mounted by the holder 18 to the mounting member so that the cutting edge 22 lies in a plane of rotation of Sthe rotor. The cutting edges 20 and 22 are typically disposed to form a 90 degree angle therebetween, for cutting a square corner C.

Referring particularly to Figure 5, the knives are preferably adapted so that a back side of the knife 17 abuts a side surface 27 of the knife 19 to form a mitered corner. For this purpose, the side surface 27 of the knife 19 is angled obliquely with respect to the cutting edge 22, and for cutting opposite comers C, left and right handed versions of the angle and, therefore, the knife 19 may be provided.

The cutting edges define lines composed of a number of points. Cutting action by each knife creates respective surfaces, typically though not necessarily planes, as a result of the cutting edges progressing through the work as a result of relative movement there between. Similarly, cutting action resulting from a particular point on a cutting edge creates a line, typically though not necessarily straight, as a result of the relative movement. In the instant invention, the mounting member is configured so that at least one of the points on one of the cutting edges is proximate at least one of the points on the other of the cutting edges. Preferably, these points are end points of the respective cutting edges and, preferably, these points abut one another, such as shown in Figure 4.

Particularly, where the cutting edges are brought into proximate coincidence at their end points their tips, it has been found that this coincidence is preferably no more than about 1/8" for notable minimization of surface irregularities such as "waviness" and feathers, with 1/16" being a more desirable outer limit for commercial practice. It has also been found that decreasing the chip size generally permits a larger separation between the points for purposes of minimizing waviness, but the generation of feathers is not substantially affected. Neither waviness nor the generation of feathers is substantially affected by the size of the knives.

In addition to rccogn izng that ii: is important to in'ange tile knives in a close tipto-Utp relationship to improve cutting finish, tile present inventors have also recognized thc importance of providing for maintaining such a relationsitip during usc of the apparatus. A chipping kifc is typically clamped to a mounting miember by a knife S holder. e bolt e.Ntendinrg through the knife holder into either the mounting nicmibcr or tile rotor. Duiring usc of thc apparatus, the bolt mnay loosen, allo-wing thc knife some latitude to slip backwardly froml the direction -of rotation. Wlicrc two knives that wcrc arranged in tip-to-tip abutting relationship slip in unequal amounts, a gap develops thercbctwvccn. Moreover, any gap so formed may become packcd with dcbris from thc log. tile packing causing the knives to spread fuirthecr and further apart from o!re another during continued use.

Corresponding mating features are provided in the 'knives 17.-ild 19 and thc mounting miember 14, to substanitially lock the knives into a selected position with respect thercto. for maintaining in abutting relationship of the Lips or thle kilves evenl when the clamnping force for holding thc knife exe rted by the holders 1 6 and I S to thle miounting miember is reduced to zero.

Ficlure 5 shows a preferred structure for this purpose, In the prcferred structure, thle knives 1 7 and 1 9 eachi include it keyway 15, and the mounting member 14 includes corresponding keys 32 and 34 that are adapted to fit close]\, the keyways 15 of thc knives.

2 0 The kcvwt\vs and kcy's 32 and 34 are adapted so that interlocking the keyways and the keys prevents movemecnt of thc knives in a direction perpendicular to their cutting cd.-cs, or in the direction of rotation of the mounting member. In the preferred structure, the keyways arc slots formied in the knives cxtending parallel to the cutting cdgcs of the knives as shown and described more fully in Carpenter ct al.. U.S. Patent No. 4,S5O,408, 2 5 incorporated by reference herein in its entirety.

Providingr for locking thc knives to the mounting member rather thanl tile holder 1 6 and 18 maintains their relative positions. The holders arc subject to loosening becausc they are particularly adapted to apply a clanmping force to thei knives which must bc 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 1C, 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 depicted in Figure 6, the knifc 17 extends into the plane of the paper and, therefore, its cuttinz cdbc 20 is always perpendicular to tile grain. However, the anglc tile )Wife edge 22 makes with respect to thc -rain changes along its path from to to 'F"This can bc appreciated by comparing Figures 7 and S. In both Figure 7 and Figure 8, the knives 1 7 and 19 are shown in a configurition for culting square corners whercin the angle 19 between the edges 20 and 22 is 90 degtrees. However. in Figure 7, Elhe knivcs are shown rclative to thle logy travel direction as they would appcar at poilnt while in Figure S, thle knivcs are show.%n relative to as they would appcar at point in Figure 6. At point (Figure both of tile cutting edges 20 and 212 are perpendicular to the travel direction and therefore Perpendicular to the vrai n.

*-iHowcvcr. at point (Figure the cutting edg~e 22 is parallel to the grain. This is undiesirablIe.

Turning to Figure 9, the present embodiment provides a selected angle between tile cutting edgec_22 and the line defined as bcing, pcrpendicular to the travel directio and the axis of rotation at point As best seen in Figure 6, thle angle (D is preferably determined by constnicting a radial line extending from the tips of the knives 1 7 and 19 to the center of thle rotor the sarnc result beine obtai ned by projecting. in a plane perpendicular to the axis of rotation, thle line excridino fromn the tips. of tile knives to any point on the axis of rotation.

Ail angular variation of the angle 0 about the tips of thle knives is preferably within about 15 degrees. As can be appreciated by inspecting Figure 6 and considering the goal of minimizing parallelism wvith the grain it is gcncrally desirable that the angle (D be greater %%,here the depth of penetration into the log (Figure as compared to the radius of the arc traveled by the tips of thle knives, is greater.

The consideration of the angle (D is substantially independent of the choice of the angle 0. For ex'ample, the projections of the cutting edges 20 and 22 in the direction of rotation of thle mounting member 14 that is responsible for the shape of the cormer "C" (Figure 1) remain 90 degrees apart regardless of the choice of the angle (D.

It is to be recognized that, while a particular knife for use in method and apparatus for profiling a log has been shown and described as preferred, other configurations could be utilized, in P:\OPER\AM4786-00 SPEdoc.-14102/03 -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 (2)

1. A knife for use in a wood profiling apparatus, said knife being mounted for rotation 00 about an axis in said profiling apparatus, said knife including first and second sides which t) 5 meet to define a cutting edge, and a third side immediately adjacent the cutting edge and O Sthe first and second sides, said third side intersecting one of said first and second sides to aC define another edge intersecting said cutting edge and lying in the same plane as the Ocutting edge, wherein the cutting edge is at an angle with respect to said third side that differs substantially from 900, and wherein said third side is perpendicular to said plane.

2. A knife, substantially as described with reference to Figures 3-9. Dated this 13th day of April, 2006 Key Knife, Inc. By DAVIES COLLISON CAVE Patent Attorneys for the Applicant