AU758287B2

AU758287B2 - Method and apparatus for profiling a log

Info

Publication number: AU758287B2
Application number: AU54786/00A
Authority: AU
Inventors: John S. Luecke; Bradley R. Stager
Original assignee: Key Knife Inc
Current assignee: Key Knife Inc
Priority date: 1999-06-08
Filing date: 2000-06-08
Publication date: 2003-03-20
Anticipated expiration: 2020-06-08
Also published as: ES2291213T3; CA2369769C; EP1192027A4; DK1192027T3; BR0011413A; EP1192027A2; EP1192027B1; AU5478600A; WO2000074910A2; CA2369769A1; DE60036213D1; ATE371527T1; DE60036213T2; WO2000074910A3

Abstract

A method and apparatus for profiling a log. In a profiler having first and second knives (17, 14) disposed on a rotating disc (12), a mounting member (14) is adapted to mountably receive both the first and second knives so that each blade has a point on its cutting edge that is proximate a point that is on the cutting edge of the other knives. Preferably, the points are end most points and abut one another.

Description

P:\OPER\Arl54786-00 SPE.doc-06/01/03 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 corner in the log that extends along the log.

To process logs into standard lumber, the logs are first slabbed on one to four sides.

To avoid waste and, because the cross-section of the log is generally round, this processing intentionally leaves four rounded corners. Referring first to Figures 1A and 1B depicting, respectively, the cross-section of the log before and after being slabbed on four sides and o then turning to Figure 1 C, the rounded corners are removed by cutting into the log along its 10 longitudinal axis corresponding reentrant corners This squares portions of the log, indicated in the Figure as that are located between the contours of adjacent corners so :that the portions are configured to be cut into pieces of standard lumber. Forming the corners C is typically referred to as "profiling" and an apparatus adapted for this purpose 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 ooo.i 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 20 disc. Referring back to Figure 1C, the first knife cuts a first leg "11" of a particular reentrant corner C and the second knife cuts a perpendicular, second leg "12" of the reentrant corner, wherein the legs 11 and 12 meet at a region of intersection "cl" of the corner C. It should be understood that the legs "11" and "12" are the visible portions of planar surfaces extending along the longitudinal axis of the log.

Another example of 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.

In both of these profilers, the first and second knives are disposed so that the first knife 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 two cuts to fail to intersect precisely at the same corner region cl and thereby fail to Sform a clean or smooth corner C. In particular, there often results, running longitudinally p PRAOPERWM\54786-0 spe.d-o6IMl/O3 -2along the corner C, "feathers" or slivers of wood partially but not completely removed from the log, or 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.

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 o 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 within an angular variation of plus or minus 15 degrees, taken about a radially outermost first tip of said one knife, from a line extending from said first tip to said axis of rotation, and the cutting edge of the other of said two knives is parallel to said axis of rotation, and 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 "irotation, 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 substantially on a line extending from a radially outermost first tip of said one knife to said axis of rotation.

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.

Preferably, 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.

It is a principle object of preferred embodiments of the present invention to provide a novel and improved method and apparatus for profiling a log or other elongate article.

POPERMArI\54786-0 .dc-06/O1/03 -3- It is another object of preferred embodiments 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 preferred embodiments 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.

oO..

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

~10 Figure 1B 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 according to a preferred 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 preferred embodiment of the present invention, 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 according to one preferred embodiment of the present invention is shown in Figures 3 and 4. The profiling apparatus is particularly adapted for profiling a log; however, it may be cmployed for profiling any elongate article. The tenn "profiling" means fundamentally to alter the shape of the article for some productive purpose.

Referring back to Figures IB and 1C, typically, this involves altering an elongate fonn such as the rounded comer "Cround" of a slabbed log into an elongate, reentrant, square corner This configures the material indicated in Figure IC as which lies between the contours of neighboring corners C into an orthorhombic 10 configuration. or "sCiares" the material. It should be borne in mind throughout that other rcentrant shapes could be formed, or comers could be formed having other angles varying from 90 degrees, where that is desirable, and the operation could be performed on clongate articles other than logs without departing from the principles of the invention.

Referring to Figure 3, a rotor 12 is provided with a desired number of mounting members 14, such as four. The rotor may be disc shaped or it may have some alternative configuration such as that shown. As shown in both Figures 3 and 4, the rotor rotates about an axis As in Figure 2, a slabbed log 8 having an elongate axis is fed toward the rotor along a circumferential direction which is represented in Figure 4 and which is perpendicular to the plane of Figure Each mounting member 14 includes two holders 16 and IS. Each holder is :*6090 adapted to clamp an 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 turn, 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 preferred embodiment. However, it is often preferable to provide these components as individual parts that are adapted to be connected together with machine screws or bolts, The holders 16 and IS are adapted for clamping their respective knives to the mounting element and for releasing the knife to allow the knife to be removed therefrom. Any of a number ofprior art holders may he employed. A particularly advantageous holder is that described in U.S. Patent No. 5.979,522, which is shaped to lit knives marketed by Key Knife, Inc.. under the trademark KEYKNIFE.

Figure 5 presents a more detailed view of a preferred mounting member 14 as shown in Figure 3. The knives 17 and 19 have respective cutting edges 20 and 22.

The knife 17 is mounted by the holder 16 to the mounting member 14 so that the cutting edge 20 extends parallel to tile 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 the rotor. The cutting edges 20 and 22 are typically disposed to form a 90 degree angle therebetween, for cutting a square comer C.

"10 Referring particularly to Figure 5, the knives are preferably adapted so that a back side of the knife 17 abuts a side surface 25 of the knife 19 to form a mitered i: corner. For this purpose, the side surface 25 of the knife 19 is angled obliquely with respect to the cutting edge 22, and for cutting opposite corners 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 '20 the relative movement. In the instant embodiment, 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/S" 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, SR 4 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 rccogniving that it is imlportanit to arrange tile knives inl a close tipto-tip relationship to improve cuttingo finish, the present ivnoshv lorcgie thc importance of providing for maintaining such a relationship during use of the apparatus. A chipping knife is typically clamipcd to a mounting! miember by a knife holder. a bolt emecnding thirough the knife holder into cither tile mounting icneber or thle rotor, Duiring usc of the apparatus, the bolt mnay loosen. allowing the knife some latitude to slip backwardly' from the dirction-of rotaion. Wherce two knives that were arrangied in tip-to-tip abutting relationship slip in unequal amrounts. a gap develops therebctween. Moreover. any gap so formled mlay becomle packed with debris fromi thc 1og. the Packing causing the knives to spread furthecr and further apart from one another *~*duringy Continued use.

Corresponding mating features are provided in the" 17 -anld 1 9 and the miounting member 14, to substantially lock the knives into a selected position with respect thercto, for maintaining in abutting relationship of the tips of the knives even when the clamping force for holding the knife exerted by the holders 1 6 and 18S to thle Mounting member is reduced to zero.

F cgure 5 shows a preferred structure for this purpose. In the preferred structure, the knives 17 and 19 each include a keyway 15, and the mounting member 14 includes corresponding keys .32 and 34 that are aclaptcd to fit closely- the keywvays 15 of the knives, Th cwsadkys 32 and 34 are adapted so that interlocking the keywvays and the keys prevents movement of the knlives in a direction perpendicular to their cuttinig cd-cs, or in the direction of rotation of the mounting member. In the preferred structure, the key-ways arc slots formied in the knives extending parallel to the cutting cdgcs of the knives as shown and described more fully in Carpenter et it.. U.S. Patent No. 4,S50,408, incorporated by reference herein in its entiretY.

Providing for locking the knives to the mounting mnember rather thanl thc holders 1 6 rind 18 maintains their relative positions. The holders are subject to loosening bec2Luse they are particularly adapted to apply a clamiping force to the knives which miust be removable in order to replace the knives.

i. SEP 200 7 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 1 C, 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.

SRAt M1EM ,E o E 0 S. 0 S S 5

SC

SS. As it is depicted in Figure 6, the knife 17 extends into the plane of the paper and, therefore, 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, the knives 17 and 19 are shown in a configuration for cutting square comers 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 point while in Figure S, the knives are shown relative to as they would appear at point in Figure 6. At point (Figure both of the cutting edges 20 and 22 are 10 perpendicular to the travel direction and therefore perpendicular to the grain.

However, at point (Figure the cutting edge 22 is parallel to the grain. This is undesirable.

Turning to Figure 9, the preferred embodiment provides a selected angle D between the cutting edge 22 and the line defined as being perpendicular to the travel direction and the axis of rotation at point As best seen in Figure 6, the angle 4 is preferably determined by constructing a radial line extending from the tips of the knives 17 and 19 to the center of the rotor the same result being obtained by projecting, in 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.

20 An angular variation of the angle 0 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 0 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 4 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 corer "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

S

P:'OPER\ArI54786-MO spc.doc-06W01/03 -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.

i 10 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 S as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

*o*oo

Claims

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 within an angular variation of plus or minus 15 degrees, taken about a radially outermost first tip of "said one knife, from a line extending from said first tip to said axis of rotation, and the cutting edge of the other of said two knives is parallel to said axis of rotation, and wherein 10 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, wherein said mounting member is adapted to mount said one knife so that the cutting edge thereof lies substantially on said line.

3. The profiling apparatus of claim 1 or 2, including said one knife, wherein said cutting edge thereof defines an angle with respect to an immediately adjacent side thereof that differs substantially from 90 degrees.

4. 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 substantially on a line extending from a radially outermost first tip of said one knife to said axis of rotation. The profiling apparatus of claim 4, wherein said mounting member is further adapted to mount said two knives so that the cutting edge of the other of said two /JRA 0 knives is parallel to said axis of rotation.

P:\OPER\Arl54786-00 SPE.doc-07/01/03 11

6. The profiling apparatus of claim 4 or 5, including said one knife, wherein said cutting edge thereof defines an angle with respect to an immediately adjacent side thereof that differs substantially from 90 degrees.

7. A profiling apparatus, substantially as described with reference to Figures 3-9. 10 DATED this 7th day of January, 2003 Key Knife, Inc. By DAVIES COLLISON CAVE Patent Attorneys for the Applicant ago *°oo