AU2003200525B2 - 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\26l4324 44.DOC 17r2103 METHOD AND APPARATUS FOR PROFILING A LOG The present invention relates to a method and apparatus for profiling a log, particularly for cutting a reentrant comer in the log that extends along the log.

To process logs into standard lumber, the logs arc first slabbed on one to four sidcs. To avoid w~vaie and. because the cross-section of the lo is generally round, this 1C processing intentionally leaves four rounded comers. Referring first to Figures IA and 1 B depicting, respectively, the cross-section of the log before and after being slabbed on four sides and then turning to Figure IC, the rounded comers are removed by cutting into the log along its longitudinal axis corrcsponding reentrant comers This squares portions of the log. indicated in the Figure as that are located bc\tween the contours of adjacent comers so that the portions are configured to be cut into pieces of standard lumber. Fomring the comers C is typically referred to as "profiling" and an apparatus adapted for this puqrose is typically referred to as a "'profiler." An.example of a prior art profiler is shown in Figure 2. First and second knives 2 and 4, which are identical, are disposed on the circumference of a rotating disc 6. A slabbed log 8 having an elongate axis is fed toward the disc along a circumferential direction The cutting edge of the first knife is oriented parallel to the axis of rotation of the disc and the cutting edge of the second knife is oriented in a plane of rotation of the disc. Referring back to Figure 1C, the first knife cuts a first leg 1" of a particular reentrant comer C and the second knife cuts a perpendicular, second leg "12" of the reentrant comer, wherein the legs 11 and 12 meet at a region of intersection "cl" of the comer C. it should be understood that the legs "ll" and "12" are the visible ponions of planar surfaces extending along the longitudinal axis of the log.

3 0 Another example of a prior an 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.

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

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

Accordingly, [here is a need for a method and apparatus for profiling a log that :rovides for the fonration of smoother surfaces in comers cut thereby and for maintaining this capability despite wear in the apparatus.

One aspect of the present invention provides a profiling apparatus adapted to rotate a-.

plurality of cutting knives having respective cutting edges about an axis of rotation, the apparatus comprising a mounting member adapted to mount two of the knives so that the cutting edge of one of said two knives lies substantially in a plane perpendicular to said axis of rotation and the cutting edge of the other of said two knives is parallel to said axis of rotation, wherein said mounting member is further adapted to mount said two knives so that a tip of said other knife and said first tip substantially abut one another.

Another aspect of the present invention provides a profiling apparatus adapted to rotate a plurality of cutting knives having respective cutting edges about an axis of rotation, the apparatus comprising a mounting member mounting two of the knives so that the cutting edge of one of said two knives lies substantially in a plane perpendicular to said axis of rotation and the cutting edge of the other of said two knives is parallel to said axis of rotation, wherein said mounting member further mounts said two knives so that a tip of said other knife and said first tip substantially abut one another.

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 method and apparatus for profiling a log or other elongate article.

P:OPERAAr2614324 claims doc-03/05/04 -3- It is another object of one embodiment of the present invention to provide 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 of the present invention to provide 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 1B is a cross-section of the log of Figure 1 A after having been slabbed.

Figure 1IC is a cross-section of the log of Figure 1IB 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 according to one embodiment of the present invention, 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 according to the present embodiment, 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 according to one embodiment the present invention is shown in Figrs 3 and 4, Tlic profiling appara(lts is particularly adipted for profiling a log; however. it may be cnployed for procling any elongate art icc. The tenn "profiling'rneans fundamentally to altcr the shape of the article for sonic produtive purpos.

Refering back to Fi2ures I and IC, typically. this involves altering an elongate fonn such as the rounded corner "Cround of a slabbed log into an eloneace, rentrant, square corner This configurcs the material indicated in Figure I C as which lies bctween the contours ofneighboing corners C into an orthorhombic coil figuration, or "squares" the miarriaf. It should be bonic in mind throughout. that oilher reentrant shapes could be formed, or corcrs could tie Formed having ocher anglcs tvarving fron 90 degrees. where that is desirabl. and the operation could bc perfamied oil clongate articles ocher than logs wiIthou dparting from the principles bf the invention.

Referring to Figure 3. a rotor 12 is provided with a desired ntinlbcr of mounting ncnbers 14. such as four. The rotor may be disc shaped or it may have some alrcmative configuration such as that shown. As sho-wn in both Figures 3 and 4, the rotor rotates about an axis As in Figure 2, a slabbed log S having an elongate axis is fed toward the rotor along a circumferential direcion "dI" which is represented in Figure 4 and which is perpendicular to the plane of Figure Each mountirg member 14 includes two holders I6 and I S. Each holder is adapted to clanmp ac associated knife 17 and 19 to the mounting member. The knives may be any cutting implements including, for example, saw teeth. The mounting member is, in trn. adapted for mounting to the rotor 12. The identification of discrete parts such as the mounting member and rotor may be somewhat arbitrary since these parts could be combined into an integral unit and function identically for purposes of the present invenion. However, it is often preferable to provide these components as individual parts that are adapted to be connccted together ith machine screws or bolts.

The holders [6 and IS are adapted for clamping their respective knives to the mounting clement and for releasing lie knife to allowv the knife to be removed therefrom, Any of a number orprior art holders may be employed. A particularly advantagcous holder is that described in U.S. Patent No. 5.979,522, which is shaped to fit knivcs marketed by Key Knifec, Inc., under the trademark JKEYKNIFE.

Figurc 5 presents a more detailed view of a preferred mounting rnienbcr 14 as showo in Figure 3. The knivecs 17 and 19 hanve respctive cu~tting" edges 20 and 22.

The knife 17 is mnounted by the holder 16 to the mnounting nicmber 14 so that the cuttinS edge 20 extenids parallel to the rotational axis of thc rotor. The knifc 19 is mounted by thc holder 18 to the rnountin.- mcmiber so that the cutting cdgc 22 lies in a plane of rotation of the rotor. The Cuttingt edges 20 and 221 are typically disposcd to forrn a 90 degree angle thcrebetween, for cutting a square cum--,I C.

Referring pirticuilarly, to IFisure 5. thec knives are preferably a;dapted so that a back side of the knife 17 abuts a side surface 25 of the knife 19 to form a mitered corner. For this pui-pose, the side surface 25 of the knifc 1 9 Is angled obliquely with respect to the cuttinvg edge 22, and for cutting- opposite corners C, left and right handed versions of the an-le and, therefore, the knife 19 may be provided.

Thc Cu~ttirIS edgecs define lines composed of a number of points. Cutting action by each knife creates respcctive surfaces, typically though not necessarily planes, as a result of the cutting edges progressing throughl th e work as aI reSult of relative movemnrt there between. Similarly, cuttill- action resulting from a particular point on a cutting cdge creates a line, typically though not necessarily straight, as a result of the relative movemient. In the instant invention, [the mounting member is coniguredl so that at least onec of the points on one of thc 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 a5 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 I S" for notable minimization of surface irregularities such as "waviness" and feathers, with 1/ being a more. desirable outer limit for commercial practice. It has also been found that decreasing the chip size generally per-mits a larger separation between the points for purposes of minimizing waviness, but the generation of feathers is not substantially affected. Nei ther waviness nor the generation of feathers is substantially affected by the siyze of the knives.

In addition to recognizing that it is important to arrange the knives in a close tipto-tip relationship to improve cutting finish, the present inventors have also recognized the importance of providing for maintaining such a reltionship during use of the apparatus. A chipping knife is typically clamped to a mounting member by a knife holder a bolt extending through the knife holder into citer the mounting member or the rotor. During use of the apparatus, the bolt inny loosen, allowing the knife some latitude to slip backwardly from thile direction of rotation. Where two knives that were arranged in tip-to-tip abutting relationship slip in unequal amounts. a gap develops therebetween. Moreover, any gap so formed may become packed with debris from the log. the packing causing the Knives to spread ftrther and further apart from one another during continued use.

Corresponding mating features are provided in the knives 17 and 19 and thle mounting member 14, to substantiaiv lock the knives into a selected position with respect thereto. for maintaining an abutting relationship of the tips of the knives even when the clamping force for holding the knife exerted by the holders 16 and IS to thile mounting mniember is reduced to zero.

Figure 5 shows a preferred structure for this purpose. in the prcfcrred structure, the knives 17 and 19 each include a keyway 15, and the mounting member 14 includes corn-esponding kcys 32 and 34 that are adapted to fit closely the keyways 15 of the knives.

The keyvavs and k)eys 32 and 34 are adapted so that interlocking the keyways and the keys prevents movement: of the knives in a direction pernendicular to their cutting edges, or in the direction of rotation of the mounting member. in the preferred structure, the keywavys are slots Fomied in the knives extending parallel to the cutting edges of the knives as shown and described more fully inll Carpenter ct al.. U.S. Patent No. 4,550,408, incorporated by reference herein in its entirety.

Providing for locking the knives to theIC mounting member rather than the holders 16 rnd 18 maintains their relative positions. The holders are subject to loosening becausc they are particularly adapted to apply a clamping force to the knives which must 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 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 knife 17 extends into the plane of the paper and, thereforc, its cutting edge 20 is always perpendicular to the grain. However, the angle the knife edge 22 makes with respect to the grain changes along its path from to to This can be appreciated by comparing Figures 7 and S. In both Figure 7 and Figure 8, tie knives 17 and 19 are shown in a configuration for cutting square comers "C" wherein the angle 0 between the edges 20 and 22 is 90 degrees. However, in Figure 7, the knives are shown relative to the log travel direction as they would appear at poin: while in Figure S, the knives are shown relative to as they would appear at point ini Figure 6. At point (Figure both ofthe cuttiin edges 20 and 22 arc perpendicular to the travel direction and therefore perpendicular to the grain.

:Howvccr. at point (Figure the cutting edge 22 is parallel to the grain. This is undesirable.

Turning to Figure 9, the present embodiment provides a selected angle 'F between the cutting edge 22 and the line defined as being perpendicular to he travel direction and the axis of rotation at point As best seen in Figure 6. the angle 0 is preferably.deternmined by constructing a radial line extending from the tips ofthe knives 17 and 19 to the center of the rotor the same result being obtained by projecting. il a plane perpendicular to the axis of rotation, the line extending from the tips of the knives to any point on the axis of rotation.

An angular variation of the angle D about the tips of the knives is preferably within about 15 degrees. As can be appreciated by inspecting Figure 6 and considering the goal of minimizing parallelism with the grain it is generally desirable that the angle 3 be greater where the depth of penetration into the log (Figure as compared to the radius of the arc traveled by the tips of the knives, is greater.

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

It is to be recognized that. while a particular method and apparatus for profiling a log has been shown and described as preferred, other configurations could be utilized, in P:ZOPERV\Ir\4786-0 SPE.doc-O.14/0203 -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 profiling apparatus adapted to rotate a plurality of cutting knives having respective cutting edges about an axis of rotation, the apparatus comprising a mounting member adapted to mount two of the knives so that the cutting edge of one of said two knives lies substantially in a plane perpendicular to said axis of rotation and the cutting edge of the other of said two knives is parallel to said axis of rotation, wherein said mounting member is further adapted to mount said two knives so that a tip of said other knife and said first tip substantially abut one another.

2. The profiling apparatus of claim 1 including said one knife, said one knife including first and second sides which meet to define the cutting edge of said one knife, and a third side immediately adjacent said cutting edge and the first and second sides, wherein said cutting edge is at an angle with respect to said third side that differs substantially from

3. A profiling apparatus adapted to "rotate a plurality of cutting knives having respective cutting edges about an axis of rotation, the apparatus comprising a mounting member mounting two of the knives so that the cutting edge of one of said two knives lies substantially in a plane perpendicular to said axis of rotation and the cutting edge of the other of said two knives is parallel to said axis of rotation, wherein said mounting member further mounts said two knives so that a tip of said other knife and said first tip substantially abut one another.

4. The profiling apparatus of claim 3 including said one knife, said one knife including first and second sides which meet to define the cutting edge of said one knife, and a third side immediately adjacent said cutting edge and the first and second sides, wherein said cutting edge is at an angle with respect to said third side that differs substantially from P.OPERIAr\2614324 claiM.doc-13 07 4 11A profiling apparatus, substantially A profiling apparatus, substantially as described with reference to Figures 3-9. Dated this 13th day of July, 2004 Key Knife, Inc. By DAVIES COLLISON CAVE Patent Attorneys for the Applicant