Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02216582 2003-O1-20
METHOD AND APPARATUS FOR SCANNING, OPTIMIZING AND EDGING A BOARD
WITH AN ACTIVE EDGER
Field of the Invention
This invention relates to a method and an apparatus for lineal or horizontal
scanning and edging of boards or flitches including skewed flitches, for
lumber, and in particular
relates to a board edging system, for the edging (rip sawing) of a board
according to an optimized
profile in an active edger having with saws and chippers so as to eliminate a
tailing device.
Background of the Invention
A board, or " flitch", by definition has first and second opposed cut planar
faces and
first and second opposed waned edges. In the prior art, flitches would be
scanned and sequenced
horizontally, positioned in the desired skew, if any, and then clamped by feed
rolls to be feed
linearly into a conventional edger. Alternatively, the flitches would be
symmetrically centered in
the direction of flow, fed through a linear scanner, and then, in the same
direction of flow, into an
edger capable of skewing and laterally translating. The first approach is
effective, but the system
is quite expensive and the positioning of the flitch can take up time. The
second approach, such as
2 0 is taught in US patent 4,599,929 to Dutina, works fine, but the system
does not take full advantage
of modern automatic controls and does not teach the requisite mechanics to do
so.
Different lineal scanning and positioning methods have been used. US patent
number 4,239,072, to Merilainen, discloses a lineal scanning and skew edging
process, but does
2 5 not allow for multiple saws. US patent number 4,449,SS7, to Makela,
discloses a similar process
to that of Merilainen '072, but lacks the ability to reduce the edgings to
chips, and also does not
allow for multiple saws.
1
CA 02216582 2003-O1-20
US patent number 5,429,161 to Allard discloses a linear scanning resawing
process.
The apparatus positions the workpiece while the workpiece is moving by means
of two pair of
tandem, opposed top and bottom, clamp rollers that skew the workpiece as it is
translated for
resawing. This process relies on twisting the workpiece as it moves through
the roller clamps.
This causes skidding of the workpiece between the rollers as they are skewed.
The variance in
friction between different workpieces and the rollers and the difference in
the direction of the
rollers' axis and the direction of the workpiece as it travels through the
roller clamps, may cause a
margin of error that reduces the recovery percentage. It is well known in the
industry that roll feed
edgers are not that accurate.
Summary of the Invention
The method and apparatus for scanning, optimizing and edging a board with an
active edger, and control thereof, consists of, first, an unscrambler that
receives and separates the
1 S flitches from the mill. The unscrambler feeds the flitches onto an even
ending roll case having a
live fence. The ending rolls even-end the flitches against the live fence, and
then transfer the
flitches to a flitch sequencing transfer table, or, for timed release, on to a
variable speed lugged
transfer table. The transfer table gathers and advances the flitches. The
profiles of the flitches are
scanned at this point if using a transverse scanning system. The flitches are
advanced for timed
2 0 release, so as to queue the flitches for release onto a chain feed, or
other type of feed table, where
the flitches are roughly positioned to "zero far side" against a fence (also
known as a line bar).
The flitches are advanced, perpendicular to the flow of the transfer table,
straight towards the
active edger. The feed table feeds the flitches singly on to a wide
circulating belt, or belt
conveyor, separated only by the distance needed to queue up the next flitch on
to the roll case.
2 5 When using a lineal scanner, the belt conveyor moves the flitches through
the lineal scanner where
the scanner reads the profiles of the flitches and sends the data to a
decision processor system.
2
CA 02216582 2003-O1-20
The advantage of "zero far side" positioning is to allow for the simplest
possible
positioning of a flitch on the feed table for feeding to the edger. This also
allows the correspond-
ing edger far side saw and/or chip head to remain in a localized area while
the opposite edger
saws) and chip head are adjusted to obtain the desired board width(s). This
reduces the tailing
solution needed behind the edger, thus reducing the complexity of the tailer
and the time needed to
make the adjustments of the tailer.
In the decision processor an optimizing algorithm generates a three
dimensional
model from the flitch's measurements and calculates the optimized edging
solution. Data is then
transmitted to a programmable logic controller (PLC) that in turn sends motion
control
information related to the optimum breakdown solution to the active edger,
which sets the start
position and controls the movement of the saws and chip heads using a motion
controller, which
may be position based.
The flitch moves from the scanner, along the belt conveyor, to a sharpehain
positioned just in front of the active edger. Overhead driven press rolls
above the sharpchain press
the flitch down against the top of the sharpchain as the flitch feeds straight
into the active edger.
The overhead pressrolls cooperate with the circulating sharpchain in the
infeed area of the active
edger to control the direction and accuracy of straight feeding. The active
edger feed area may
2 0 also have split bedrolls in the infeed area. Non-split bedrolls may be
provided in the outfeed area,
also having overhead pressrolls. The flitch is pressed down by the overhead
pressrolls onto the
lower infeed sharpchain and bedrolls as the flitch is fed straight into and
through the edger saws
and chip heads. The saws and chip heads actively follow the optimum path
unique to the flitch,
the saws reducing the flitch to boards, the chip heads reducing the edgings to
chips.
The sawing device rotates the guides and saws on an axis perpendicular to the
flow,
and simultaneously translates the guides and saws transversely to the flow to
accomplish active
cutting of a workpiece. The chip heads clean up the edgings.
3
CA 02216582 2003-O1-20
The efficiency of lumber production from flitches, and in particular for
irregular or
crooked flitches, is improved by placing the flitch against a fence to the
"zero far side" of a
conveyor. The conveyor then moves the flitch through a lineal scanner, if not
already scanned on a
transverse scanner. The flitch is moved straight in the direction of flow
through the edger, where
the saws and chip heads skew and actively translate in unison to saw and chip
the flitch. Conical
chip heads can be mounted with a toe-in equal to the maximum skew of any given
flitch, which
allows the chip heads to remain substantially perpendicular to the direction
of flow as the chip
heads translate perpendicular to the flow along with the saws, which must skew
and translate to
cut the skewed flitch as desired. By attaching chip heads immediately behind
the saws and in the
saw feed line, and translating the chip heads along with the saws, the need to
handle the edgings
after they exit the edger is eliminated.
The efficiency of lumber production from flitches, and in particular for
irregular or
crooked flitches, is also improved by employing position-based motion controls
for use with the
active edger, which motion controls follow the cutting solution for each
flitch as determined by
both the optimizer from the scanned profile of the flitch and the desired
lumber prerequisites.
Controlling the saws through the guides, as set out in more detail below, by
cutting
2 0 a gentle curve along the profile of a given flitch, in certain situations
and given sawmill requisites,
allows for increased board length and thus increased recovery percentage. This
is achieved by
accurate control of the saws by means of the saw guiding system described
below and the position
based motion controls working in cooperation with the optimizer which can be
programmed to
recognize a situation where a gentle curve may improve recovery percentage.
By the edger saws skewing and translating, and the edger chip heads
translating in
unison with the saws, so as to traverse the skew of the flitch as the flitch
moves through the edger,
the flitch only moves through the edger straight, in the direction it was
scanned. The edger saws
CA 02216582 2003-O1-20
and chip heads adjust for width and skew for starting position, and then
translate together actively,
to traverse the flitch by translating the saws and chip heads as the flitch
moves through the edger
so as to cut along the optimized path that has been determined by the
optimizer.
An infeed anvil may be positioned tightly adjacent the bottom of the chip
head(s),
The anvil directs the edgings into the chip heads) and prevents the edgings
from being deflected
down by the chip heads) rotational cutting forces. The chip heads) may be
conical or drum-like,
and may have compound angled knives that slice rather than chop the edgings,
thus producing
better quality chips. The infeed anvil and the chip heads may be positioned in
the saw feed line
and close to the rear, that is, the downstream end of the saw blades, and may
be attached to the
same positioner cylinders for simultaneous translation of the chip heads and
the saws. Outfeed
vertical faced anvils may also be placed behind the chip heads to counteract
any forces that the
opposing chip head may cause. An opposing roller may be provided, cushioned
and adjustable, so
as to inhibit the zero far side chip head forces from pushing the Hitch off
the feed line, when using
only one chip head on the far side.
In an alternate chipper disc configuration, V-shaped wing knives are provided
which prevent edging slivers from being forced between the chipping disc and
the board.
2 0 The chip heads are used to reduce the edgings of the flitch so that there
is no need
to handle the edgings behind the edger.
In summary, and not so as to exclude the above, the active edger in a first
embodiment of the present invention includes an actively positionable gangsaw
or a first end saw
2 5 mounted on an arbor mounted within a stationary saw box, wherein the
gangsaw or first end saw is
actively positionable relative to the saw box. In a second embodiment, the
gangsaw or first end
saw is mounted on an arbor in fixed translational and skewing relation
relative to, and within, an
actively positionable saw box. The actively positionable gangsaw is
selectively actively laterally
5
CA 02216582 2003-O1-20
translatable and selectively actively rotatable so as to skew the gangsaw
relative to the saw box. In
both embodiments, the saw box receives a workpiece, longitudinally conveyed in
a downstream
direction, longitudinally into the gangsaw or first end saw from an upstream
position. A first
chipping head, mounted to a first side of the saw box adj acent and downstream
of the first end saw
or a first end saw in the gangsaw is, in the first embodiment, selectively
actively laterally
positionable so as to align with a first feed line corresponding to the first
end saw in unison with
active positioning of the gangsaw, relative to the workpiece. In both
embodiments, the first
chipping head actively corresponds, in a lateral chipping depth, to a lateral
edging dimension of a
sawn edging sawn from the workpiece. The sawn edging is chipped as the
workpiece is conveyed
from, once sawn by, the gangsaw, longitudinally past the first chipping head.
In one aspect of the present invention, the active edger further comprises a
second
actively laterally positionable chipping head mounted to a second side of the
saw box, where the
second side is opposite to the first side of the saw box. The second chipping
head may be
downstream of a second end saw mounted on the arbor in the saw box, and
actively laterally
positionable so as to actively align with a second feed line corresponding to
the second end saw,
and so as to actively laterally position in unison with the second end saw.
The second chipping
head may be adjacent the second end saw and mounted in generally opposed
facing relation to the
first chipping head, or may be staggered, relative to the first chipping head,
in a downstream
2 0 direction. Advantageously, in the first embodiment, the first and second
chipping heads are
aligned with toe-in relative to the alignment of the first and second end
saws.
In a further aspect of the invention the saws are positioned by positioning
saw
guides corresponding to saws on the gangsaw. The saw guides are selectively
rotatable about
2 5 corresponding generally vertical axes of rotation whereby rotating the
guides skews the saws. The
guides are positioned by selectively rotatable generally vertical shafts
corresponding to the guides,
and rigidly mounted thereto. Selective rotation means selectively rotate the
shafts about their
6
CA 02216582 2003-O1-20
longitudinal axes to thereby rotate the guides and the saws. The selective
rotation means may be
actuator driven worms and mating worm gears for selective rotation of the
shafts.
The active edger of the present invention advantageously further includes
means for
cantilevering the workpiece over a gap in a workpiece conveyor. The gap is
downstream of the
active edger. The cantilever means is a means for cantilevered supporting of
the workpiece, but
not the sawn edging, whereby the sawn edging may fall into the gap as the
workpiece is conveyed
over the gap by the workpiece conveyor.
The invention provides other advantages which will be made clear in the
description of the preferred embodiments.
Brief Description of the Drawings
The invention will be better understood by reference to drawings, wherein:
Figure 1 is a plan view according to a preferred embodiment of the invention;
Figure 2 is an enlarged partially cut away plan view of a portion of Figure 1.
Figure 3 is a plan view according to an alternative embodiment of the
invention,
showing one saw blade and staggered chip heads.
Figure 4 is a plan view according to a further alternative embodiment of the
2 5 invention, showing a translating and skewing saw box with two chip heads.
Figure 5 is a plan view according to a further alternative embodiment of the
invention, showing a translating and skewing saw box with one chip head.
7
CA 02216582 2003-O1-20
Figure 6 is an elevation view according to the preferred embodiment of the
invention, taken along section line 6-6 in Figure 1.
Figure 7 is an elevation view according to an alternative embodiment of the
invention.
Figure 8 is an enlarged partially cut away view of a portion of Figure 6.
Figure 9 is a section view along line 9-9 in Figure 8, showing worm gears
within
the guide block.
Figure 10 is an elevation view of the simplified tailer.
Figure 11 is a plan view of the simplified tailer of Figure 10.
Figure 12 is a plan view of an alternative chip head.
2 0 Figure 12a is an elevation view of the alternative chip head of Figure 12.
Figure 13 is an enlarged partially cut away view of a portion of Figure 1 with
the feed table modified as an alternative embodiment.
Figure 14 is, in perspective view, a block schematic diagram showing the
relationship of the electronic devices.
8
CA 02216582 2003-O1-20
Detailed Description of Preferred Embodiment
Referring to the drawing figures wherein similar characters of reference
represent
corresponding parts in each view, or preferred embodiment of the active edges
apparatus is
generally indicated by the reference numeral 10 and is best seen in Figures 1,
2 and 6.
As illustrated in Figure 1, unscrambles 12 receives flitches 14 from the mill
in
direction A. Flitches 14 are separated by unscrambles 12 and then fed onto an
even ending roll
case 16 which ends the flitches onto live fence 16a. Flitches 14 are then
transferred on to a flitch
transfer table 18, or a dropout I 9. Dropout 19 allows the operator to reject
a flitch before it moves
on to transfer table 18. Transfer table 18 advances flitches 14 by the use of
duckers. Duckers are
rows of retractable stops which pivot on common shafts to insert stop arms
into the flow of
flitches. The duckers allow control, in a stop/start manner, of the flow of
flitches across the
transfer table. Thus on transfer table 18 the flitches transfer to ducker A20
which, when raised,
stop further movement of the flitch. When ducker B22 on transfer table 18
becomes available,
flitch 14 is sequenced from ducker A20 to ducker B22 where once again the
flitch may be stopped.
When ducker C24 on transfer table 18 becomes available, flitch 14 is sequenced
from ducker B22
to ducker C24. When ducker D26 on transfer table 18 becomes available, flitch
14 is sequenced
from ducker C24 to ducker D26. When ducker E28 on transfer table 18 becomes
available, flitch
2 0 14 is sequenced from ducker D26 to ducker E28.
In an alternative embodiment, a variable speed lugged transfer table with
lugged
transfer chains (not shown) may also be employed. Timing skids (not shown),
mounted near
dropout 19, would hold back the flow of flitches 14 for timed release on to
the lugged transfer
2 5 table.
Feed table 30 receives flitches, one at a time, 14 from ducker E28. Feed table
30
moves flitch 14 against fence 32. Once flitch 14 contacts fence 32, feed table
30 begins to
9
CA 02216582 2003-O1-20
translate flitch 14 in direction B. Flitch 14 moves from feed table 30 and
fence 32, onto a wide
circulating belt 36, which continues to translate flitch 14 in direction B. A
driven overhead press
roll 34, mounted near the upstream end of belt 36, assist in accelerating
flitch 14 on to belt 36.
Flitch 14 translates on belt 36 through lineal profile scanner 38. Lineal
profile scanner 38 obtains
an image of flitch 14.
In an alternative embodiment an x-ray grade scanner 39 may be mounted
adjacent,
that is, in opposed relation above and below belt 36, upstream or downstream
of lineal profile
scanner 38. This X-ray grade scanner 39 may be of the type described in US
patent 4,879,752 to
Jan Aune. The incorporation of X-ray grade scanner 39 in this manner may
provide better
optimization of the breakdown of flitch 14.
As best seen in Figures 2 and 6, a plurality of driven pressrolls 40, each
actuated by
pressroll cylinders 40a, receive flitch 14 prior to flitch 14 entering active
edger 10. Pressrolls 40
press down to hold flitch 14 against the sharpchain 42, and onto split
bedrolls 44 if so provided.
Driven pressrolls 40 and sharpchain 42 drive flitch 14 in a straight line in
direction B into active
edger 10. Saws 46, 48 and 50, and chip heads 52 and 54 translate in direction
E as flitch 14 moves
through edger 10. Chip heads 52 and 54 are shown with toe-in of approximately
2.5 degrees.
Toe-in allows chip heads 52 and 54 to traverse flitch 14 without the need to
actively skew chip
2 0 heads. Active edger 10 includes saw guides 56, which contact both sides of
saws 46, 48 and 50 to
provide stability to the saws as flitch 14 passes through the active edger.
Within active edger 10, saws 46, 48 and 50 are rotated by, and are
translatable
on splined saw arbor 53. Saw blades 46, 48 and 50, via saw guides 56
translates saw blades
2 5 46, 48 and 50 in direction C and skew in direction D.
As best seen in Figures 8 and 9, saw guides 56 are attached to, and skewed, by
shaft
58, shown in dotted outline in Figure 8, within saw guide block 60. Saw guide
shaft 58 rotates
CA 02216582 2003-O1-20
saw guides 56, thus skewing saw guides 56 and saws 46, 48 and 50 to the
correct angle, that is,
corresponding to the skewed Hitch 14. Worm gear 62 and corresponding worm 64
within saw
guide blocks 60, mate shaft 58 to shaft 66 so that rotation of shaft 66
rotates shaft 58. Spine or
keyway 66a allow worm 64 to slide on shaft 66, while rotating with shaft 66.
Shaft 66 is rotated
by TemposonicTM cylinder 67 (cylinder 67 may also be rotated by other means of
precise
controlled translation, such as stepper motors), through linkage 67a. Shaft 66
remotely actively
skews the array of saw guides 56 corresponding to saws 46, 48 and 50 to follow
the skew of flitch
14 as flitch 14 is translated through the saws. Saw guide blocks 60 are
translated laterally by
TemposonicTM cylinder shafts 70, 72 and 74 to first set saw spacing and then
to actively translate
saws 46, 48 and 50 with spacing set to the optimizer decision which
corresponds to the skew of
flitch 14, thereby allowing saws 46, 48 and 50 to actively traverse skewed
flitch 14, or to gently
curve edge flitch 14, as the case may be, (cylinder shafts 70, 72 and 74 may
also be translated by
other means of precise controlled translation, such as stepper motors).
In an alternate embodiment, as best seen in Figure 3, active edger 10 has only
one
saw 46 on arbor 53, and chip heads 52 and 54 are staggered. As flitch 14
enters active edger 10,
saw 46 and chip heads 52 and 54 translate into position in direction E, and
continue to actively
translate so as to follow the profile of flitch 14 as flitch 14 passes through
active edger 10. Saw 46
saws the far side of flitch 14. Chip head 52 then chips the sawn edging as
flitch 14 passes chip
2 0 head 52. Side cushioned roller 52b adjusts to confirm the position of
flitch 14. As flitch 14 passes
chip head 52, the far side edge 14a is steadied by anvil roller 52b, which
steadies flitch 14 as flitch
14 moves into chip head 54. Chip head 54 chips the near side edge 14b off
flitch 14. This
embodiment may be used in a single board solution, where only one board is
produced from flitch
14.
An alternative embodiment feed table 30 is shown in Figure 13. Feed table 30
is
used in conjunction with a transverse scanner (not shown), where flitch 14 is
scanned as flitch 14
moves across transfer table 18 to feed table 30. A plurality of positioner
cylinders 31 are provided
11
_ r~.. ..._,_...__...__
CA 02216582 2003-O1-20
to replace fence 32. The number of positioner cylinders depends on the lengths
of flitches the
system can process. Positioner cylinders 31 are in line with transverse
scanner lasers (not shown)
mounted to the transverse scanner, spaced apart in equally spaced transverse
array, the transverse
scanner mounted for example transversely across the transfer table. Positioner
cylinders 31 may
be set to position flitch 14 so that minimal movement of saws in edger 10 are
needed. Positioner
cylinders may extend a little after flitch 14 has been placed on feed table
30, thereby insuring the
position of flitch 14 is known, even if the flitch has bounced. In this case,
positioner cylinders 31
are set back the anticipated distance corresponding to the desired bounce
correction, (flitch sizes
may vary the extension of positioner cylinders from one system to another).
Thus, flitch 14 may
be positioned on the desired feed line on feed table 30.
Positioner cylinders 31 may be simple air cylinders that stroke out to insure
that the
position of flitch 14 is known and accurate (as scanned). Alternatively,
positioner cylinders 31
may be Temposonic TM type cylinders, (or by other means of precise controlled
translation, such as
stepper motors). Temposonic TM type positioner cylinders 31 may be used to
straighten a skewed
flitch 14 to thereby reduce the need for edger 10 to skew. Temposonic''~M type
positioner cylinders
31 may be programmed to actively decelerate flitch 14, to thereby reduce edge
crush, which causes
a loss of recovery percentage, at the same time (i) allowing for increased
speed of flitch placement
on feed table 30 and, (ii) also thereby eliminating ditch bounce. LJse of
TemposonicTM cylinders
2 0 may allow the manufacture of a single type of active edger, independent of
the method of scanning
(transverse of lineal) employed. This reduces the number of types of edgers,
and thus reduces their
cost.
In further alternative embodiment, as best seen in Figure 4 and 7, active
edger 10
2 5 skews in direction D on pivot axis 76. Active edger 10 skews in direction
D and translates in
direction E to position saw 46 and chip head 52 to begin edging a skewed
flitch 14. The skew is
then fixed. Concurrently, the spacing of saws 48 and 50 is set. The near side
chip head 54 spacing
is set along with near side saw 50. Thereafter, the active translation of
active edger 10 in direction
12
CA 02216582 2003-O1-20
E follows the optimum line to edge the board as Hitch 14 reaches saws 46, 48
and 50. Active
skewing of edger 10 may be required for sawing a gentle curve when edging of a
flitch if desired.
In another embodiment as best seen in Figure 5, active edger 10 skews in
direction
D on pivot axis 76. Active edger 10 skews in direction D and translates in
direction E, positioning
saw 46 and chip head 52 for edging the skew of flitch 14. The skew is fixed,
the saw spacing of
saws 48 and 50 set, and then only the translation of active edger 10 in
direction E occurs to follow
the optimum line to edge the board. The active skewing of edger 10 may be
needed for sawing a
gentle curve when edging of a flitch. In this embodiment only one chip head 52
is used and an
adjustable cushioned roller 54b on the near side 14b may be employed. Roller
54b helps ensure
the position of flitch 14, as flitch 14 is moved through edger 10 in direction
B. Out feed anvil 52d
may be provided where the far side edge 14a, which has just been sawn, further
assisting to
stabilize position of flitch 14 as it moves through edger 10.
Referring again to the embodiment seen in Figure 2, as flitch 14 moves through
edger 10, the edgings (not shown), to be formed by the cutting away of waned
edge slabs 14c and
14d by saws 46 and 50, are directed at chip heads 52 and 54 as the edgings
move along with flitch
14 in direction B. Infeed anvils 52a and 54a assist in reducing the edgings
created by saws 46 and
50 to chips, by directing edgings into chip heads 52 and 54. The chips created
fall away on to a
2 0 sawdust and chip conveyor (not shown). Driven pressrolls 40 continue
pressing flitch 14 on to bed
rolls 44 on the outfeed of edger 10. Pressrolls 40 are lifted, by actuation of
cylinders 40a, as the
trailing end of the flitch 14 passes through edger 10 onto outfeed belt 86. As
shown in Figure 12
and 12a, anvil 52a may include side fence 52b to redirect any loose edgings
back into chipping
head 52. Loose edgings may otherwise move off to the side, away from chipping
head 52.
2 5 Similarly, anvil 54 may include side fence 54b (not shown).
Figure 12 and 12a also illustrate an improved chip head 80 having V-shaped
wing
knives 82. V-shaped wing knives 82 direct the edgings into the mid portion of
chip head 80, to
13
CA 02216582 2003-O1-20
prohibit slivers being forced between the chip head and sawn edge of flitch
14. The illustrated
angle 82a of V-shaped wing knives 82 is not to scale, although angle 82a
should have a defined
angle akin to the angle shown. The rest of the chip head may be a cone or drum-
like.
A simplified tailer 84 is seen in Figure 10 and 11. Tailer 84 works in
conjunction
with the above embodiments when only one chip head 52 is used on the far side
14a. Tailer 84
cooperates with edger outfeed belt 86. Edger outfeed belt 8G has an overhead
press roll 88
adjacent its downstream end, downstream in the direction of flow, direction B.
Pressroll 88 holds
flitch 14 (now a board, or boards) down on to belt 86. Roller 90 under belt 86
prevents the action
of overhead press roll 88 pressing on Hitch 14 from slowing outfeed belt 86.
Overhead press roll
88 cantilevers Hitch 14 over a gap 92. The near side edging of flitch 14 falls
through gap 92 onto a
conveyor (not shown). Because of the shape of the edgings and because that
they are not
supported by the overhead press roll 88, the edgings simply fall off to the
side of flitch 14.
Overhead press roll 88 may be adjustable in direction E depending on mill
requisites. Depending
on how long and how wide the boards coming out of the edger are, and what
their skew maximum
is, dictates whether there is a need for a side to side adjustment of overhead
press roll 88.
Secondary outfeed belt 94 cooperates with a secondary outfeed hold down means
such as pressroll
96. Secondary outfeed hold down 96 supports boards) as they are moving over
gap 92. Near side
fence 98 redirects boards) back into the direction of flow, direction B. Near
side fence 98 is
2 0 needed when the lengths of flitch 14, in combination with flitch 14 skew
maximums, cause
boards) to move off track. Secondary outfeed belt 94 can be an adjustable
belt, adjustable in
direction E or direction B if needed, again depending on mill requisites,
where lengths and skew
maximums require greater machine flexabilities.
2 5 As best seen in Figure 14, an optimizer decision processor 100 and the
scanner 38
communicate on a common scanner local area network 102. There is an ethernet
local area
network (LAN) 104 and a network server 106 for network communications, and a
modem 108 for
14
CA 02216582 2003-O1-20
external communications. The man-machine interface 110 and primary workstation
112 also
communicate over the ethernet LAN 104.
The optimizer decision processor 100 and associated network server 106,
man-machine interface 110, programmable logic controller (PLC) 114 and primary
work station
112 communicate across a common ethernet LAN 104 which is available as a
connection point to
existing mill networks. This connection point allows workstations within the
existing mill offices
(with appropriate software) access to all flitch optimization functions. A
dedicated
communications link 116 may exist between the optimizer decision processor 100
and the
programmable logic controller (PLC) 114. All workstations and the network
server 106 contain
applications which provide mill personnel the tools they require to define
their environment
(scanner, optimizer, machine center, products, shift schedules, reports) to
the flitch optimizer
system; pre-generate various start-up configurations; start, stop and load the
system; visually
monitor the flitch 14 as it proceeds through the machine centers and monitor
the operation for
unusual conditions. The operators console 118 allows the operator to stop the
movement of
flitches 14 or divert a flitch through dropout 19.
Modem 108 attached to the network server 106 and the primary workstation 112
using remote access software and appropriate controls, allows remote dial-up
access to the mill
2 0 site for software reprogramming and remote operation of almost every
application and function as
well as retrieval of statistics and flitch summaries for oft=site service
analysis. The man-machine
interface 110 provides operator input and allows the operator access to
various levels of machine
operation and control. The PLC 114 and motion controllers 120, share the task
of monitoring
speed and position of the flitch 14 and controlling positioners. Encoders (not
shown) on belt 36,
2 5 provide tracking information relative to the movement of the flitch 14.
It is apparent then that variations and modifications of the invention can be
made
without departing from the spirit or scope thereof. Such variations might
include, zero near side
CA 02216582 2003-O1-20
positioning, which would essentially apply the same rules as "zero far side"
positioning, except the
action of the feeding table 30 would be slightly different than that depicted
herein. Such variations
and modifications are meant to be comprehended within the scope of the
invention.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is to be
construed in accordance with the substance defined by the following claims.
16
