Note: Descriptions are shown in the official language in which they were submitted.
CA 02277331 1999-07-07
LOG
FIELD
This invention relates to a method of scanning and
cutting tree-length logs or stems, by means of an automatic
log-cutting apparatus which is designed to rapidly process
the logs into segments of optimum character - that is,
segments of varying lengths such that maximum value is
derived from each log.
BACKGROUND OF THE INVENTION
Traditional systems which have been developed for the
purpose of achieving optimum value from a tree stem are
often unnecessarily complex, thereby making them relatively
expensive to both construct and maintain. In addition,
traditional systems often suffer from slow processing and
handling times, the times required to initially determine
the optimum cut locations in the stem and subsequently
perform those cuts to produce the optimum segments.
2o U.S. Patent No. 4,468,993 issued September 4, 1984 to
McCown et al., discloses a small log bucking system where a
log is scanned to obtain data to select cut locations. A
computer selects cut locations based on the data obtained
during the scan and shows the locations on the log through
the use of lasers projected onto the log. An operator has
the choice of accepting or rejecting the cut locations. If
the cut locations are accepted then the operator issues the
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command to have the log brought into the cutting position.
If the cut locations are rejected by the operator then the
operator issues a command to alter the cut locations and
the computer recalculates the cut locations and again
projects them onto the log. If the cut locations are
accepted then the operator issues the command to have the
log brought into the cutting position otherwise the cut
positions are altered once again. Then the log has been
brought into the cutting position by placement on the
cutting bed, the log is clamped into place, the log cutting
saws are moved to the cutting locations previously
specified and the log is cut. This process is slow and
unduly complex because it involves the use of only two saws
and it requires an operator to verify each of the computer
s5 calculated cut locations before the log can be cut. Also,
this process is slowed further as a result of the log
cutting saws being moved only after the log has been placed
in the cutting bed and the need to clamp the log. The
number of cut locations is also limited as a log can not be
2o cut in a location where there is a cutting bed support.
U.S. Patent No. 5,579,671 issued December 3, 1996 to
Bowlin, discloses an automatic stem cutting apparatus
comprising one fixed and multiple linearly adjustable saws.
25 A log is scanned and the information from the scan is fed
to a computer which in turn calculates the cut locations
for the log. The adjustable saws are then positioned in
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accordance with the computer determined cut locations. A
stem loader then transfers the log to the saw carriages.
Once on the saw carriages, the log is positioned and
clamped into place where it is then cut by the saws as the
saw blades swing forward. The cut segments of the log are
then pushed from the saw carriage by a segment ejector to
fall to an output conveyor. This systems too suffers from
slow processing time and unnecessary complexity. The
handling time for a log is unnecessarily long and complex
1o due to the use of the segment loader and segment ejectors.
The system is also limited in that all the saws are not
linearly adjustable.
It is, therefore, an object of this invention to provide
an improved means of automatically scanning and cutting a
log into segments of optimum value. A further object of
the invention is to provide a log-cutting apparatus which
is both less complex and requires less processing and
handling time than other known systems, thereby allowing
2o for greater cost effectiveness and efficiency.
SLJn~4ARY OF THE INVENTION
These and other objects of the invention are provided
in a new and improved log-cutting apparatus, or log
merchandiser, which includes a loading apparatus and a
plurality of movable, rail-mounted log-cutting assemblies
with each assembly having two cradle arms and a log-cutting
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saw. The log-cutting assemblies can be positioned prior to
the loading of a log. The pre-positioning of the log-
cutting assemblies is achieved in accordance with scanning
data, which yields the characteristics (e. g., length,
diameter, location of knots, etc.) of the log, and with the
aid of computer program information, which determines the
optimum cut locations and positions the log-cutting
assemblies accordingly.
A series of conveyors receive and transport a log to a
log singulator which separates the logs to ensure only one
log enters the saw gallery at a time. Once singulated,
each log is passed to a second conveyor, where the log is
scanned and the information fed to a computer which
positions the log-cutting assemblies to achieve the optimum
cuts. After scanning, the second conveyor transports the
log onto the hydraulically-operated log-support arms, or
cradle arms, of each log-cutting assembly. There is one
cradle arm on either side of each log-cutting saw blade.
2o Once a log is conveyed onto the cradle arms of the log-
cutting assemblies, the saw blade of each of the log-
cutting assemblies are pivoted down in concert to cut the
log at the optimum locations. Each saw blade is located at
one end of the log-cutting saw beam, which is pivotally
connected to the log-cutting saw box. The log-cutting saw
beam is pivoted by a hydraulic piston cylinder unit located
at'the opposite end of the log-cutting saw beam. Once the
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cuts are made, the cradle arms pivot down and away,
dropping the cut segments onto the output conveyer for
transport and further processing.
Other objects and advantages of the invention will
become clear from the following detailed description of the
preferred embodiment, which is presented by way of
illustration only and without limiting the scope of the
invention to the details thereof.
1o
BRIEF DESCRIPTION OF THE DRANINQS
The invention itself both as to organization and method
of operation, as well as additional objects and advantages
thereof, will become readily apparent from the following
i5 detailed description when read in connection with the
accompanying drawings, wherein:
FiQ. 1 is a plan view of an embodiment of the log
merchandiser;
Fig. 2 is a plan view of an alternate embodiment of
the log merchandiser;
FiQ. 3 is a side view of a log-cutting assembly in the
pre-cutting position;
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FiQ. 4 is a side view of a log-cutting assembly
showing the side opposite to that shown in Fig. 3;
Fig. 5 is a side view of a log-cutting assembly in the
post-cutting position;
FiQ. 6 is a plan view of a log-cutting assembly; and
FiQ. 7 is a back view of a log-cutting assembly.
DETAILED DESCRIPTION OF THE PREFERRED Eb~ODI~NT
Throughout the figures, like elements are indicated by
like reference numbers. Referring to Fig. 1, the log
merchandiser 10 is comprised of a plurality of conveyors
12, 16, and 18, a transverse scanning apparatus 20 and a
plurality of log-cutting assemblies 30, 32, 34, 36, and 38.
It is important to note that each of the conveyors 12, 16
and 18 may be comprised of a single conveyor or a plurality
of conveyors used in series.
The first conveyor 12, transports the logs to the log
singulator 14. The log singulator separates and
singulates the incoming logs and prevents more than one log
from being loaded onto the second conveyor 16. While each
log is on the second conveyor 16, a transverse scanner 20
scans the log to determine its salient characteristics.
After a log is scanned, the scanner computing system 24
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(shown as a box) calculates the optimum locations at which
to cut the log and instructs the log-cutting assemblies 30,
32, 34, 36, and 38 to move to the appropriate positions
along the saw assembly rails 60. All of the log cutting
assemblies are laterally adjustable making it unnecessary
to align the log with a preset log zero line. After
scanning, the log is conveyed to the saw gallery 28. Once
the log is in the saw gallery 28, the log is cut by log-
cutting assemblies 30, 32, 34, 36, and 38. After cutting
so is complete, the log segments are allowed to drop onto
output conveyor 18 for further processing.
Referring to ~iQ. 2, an alternate embodiment of the
log merchandiser 10 is shown. The log merchandiser 10 of
z5 this embodiment is comprised of a plurality of conveyors
12, 16, 18, 54 and 56, a linear scanning apparatus 22 and a
plurality of log-cutting assemblies 30, 32, 34, 36, and 38.
As with the previous embodiment, each of the conveyors 12,
16, 18, 54 and 56 may be comprised of a single conveyor or
2o a plurality of conveyors used in series.
The first conveyor 12, transports the logs to the log
singulator 14. The log singulator separates and
singulates the incoming logs and prevents more than one log
25 from being loaded onto the linear conveyor 54. As each log
is transported along the linear conveyor 54, a linear
scanner 22 scans the log as it passes, to determine its
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salient characteristics. After a log is scanned, the
scanner computing system Z4 (shown as a box) calculates the
optimum locations at which to cut the log and instructs the
log-cutting assemblies 30, 32, 34, 36, and 38 to move to
the appropriate positions along the saw assembly rails 60.
All of the log cutting assemblies are laterally adjustable
making it unnecessary to align the log with a preset log
zero line. After scanning, the log is conveyed to the log
transfer assembly 26 which transfer the log from the linear
1o conveyor 54 to a bi-directional conveyor 56 which positions
the log prior to passing it to the second conveyor 16. As
described earlier, the second conveyor 16 transports the
log to the saw gallery 28. Again, once the log is in the
saw gallery 28, the log is cut by log-cutting assemblies
i5 30, 32, 34, 36, and 38. After cutting is complete, the log
segments are allowed to drop onto output conveyor 18 for
further processing.
As all of the log-cutting assemblies 30, 32, 34, 36,
2o and 38 operate in the same manner, and are comprised of the
same components, reference will only be made to a log-
cutting assembly 30 to avoid unnecessary repetition.
Referring now to Figs. 3 to 7, alternate views of the log-
cutting assembly 30 are shown. The log-cutting assembly 30
25 uses linear positioner 40 to travel along the saw assembly
rails 60. The linear positioner 40 consists of a hydraulic
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cylinder and a digital probe (not shown) to locate the
position of each linear positioner.
The linear positioner 40 is secured to the log-cutting
saw box 62 of log-cutting assembly 30 via the linear
positioner mount 50.
Movement of the log-cutting assembly 30 along the saw
assembly rails 60 is facilitated by the wheel assemblies 63
1o and 64. The wheel assemblies 63 and 64 are mounted to the
log-cutting saw box 62 at the front and rear, respectively.
The log-cutting saw beam 68 is mounted to the top of
the log-cutting saw box 62 through the saw mount 66. The
i5 saw blade 70 is mounted at one end of the log-cutting saw
beam 68 via the arbor assembly 80 and the saw motor 74 is
mounted at the opposite end of the log-cutting saw beam 68
through the motor mount 76. The saw motor 74 rotates the
saw blade 70 via the belt 78 which connects the saw motor
2o sheave 82 to the saw blade sheave 72. The saw blade 70 is
shielded by a saw guard 58. The log-cutting saw beam 68
reversibly pivots around pivot 88 between a log cutting
position and a non-log cutting position. The log-cutting
saw beam 68 is reversibly pivoted through the action of the
25 hydraulic cylinder 84 which has one end mounted to log-
cutting saw box through cylinder mount 85 and the second
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end pivotally mounted to the log-cutting saw beam 68 via
pivoting cylinder mount 86.
Also the cradle arms 90 are mounted to log-cutting saw
box 62 through the cradle supports 102. The cradle arms 90
are mounted on either side of the saw blade 70 and connected
together via a cradle bar 92. The cradle bar 92 ensures
that the cradle arms 90 move in unison. The cradle arms 90
are reversibly pivotal about the cradle pivots 94. A
1o hydraulic cylinder 96 has one end pivotally mounted via a
pivotal cylinder mount 97 and the other end mounted to the
cradle bar 92 via a pivotal cylinder mount 98. The
hydraulic cylinder 96 allows the cradle arms 90 to move from
a log-cutting position that supports a log as it is being
i5 cut to a non-log-cutting position where the cradle arms 90
retract back towards the log-cutting saw box 62 and thereby
release the cut log segments onto the output conveyor 18
(see Fig. 5). The log supporting portion of the cradle arms
90 have teeth 100 which prevent the log from spinning in (or
20 out of) the cradle arms 90 when the saw blade 70 is lowered
to cut the log.
In operation, the log merchandiser 10 cuts tree-length
logs or stems into segments that maximize the value derived
25 from each log as follows. Referring to FIGS. 1-7, logs are
delivered to first conveyor 12 transversely, in a linear
sequence. The logs are transported via first conveyor 12
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to the log singulator 14. The log singulator 14 separates
the incoming logs and allows only one log at a time onto
the second conveyor 16 or the linear conveyor 54. The
operation of the conveyors 12, 16, 18, 54 and the log
singulator 16 are controlled by the scanner computer 24.
From commands issued from the scanner computer 24, an
incoming log is transported, scanned, cut and the cut
portions transported for further processing. In one
embodiment, the log is scanned as it rests on the second
1o conveyor 16. In an alternate embodiment, the log is
scanned as it passes by the scanner while being transported
by the linear conveyor 54. The scanner 20 or 22, depending
on the embodiment, scans the log to determine the physical
characteristics of the log. The physical characteristics
s5 of the log, obtained by the scanner 20 or 22, are then
transferred to the scanner computer 24. The scanner
computer 24, based on the information obtained from scanner
20 or 22, calculates the optimum cut locations for the log.
The scanner computer 24 then issues commands to the
2o respective linear positioners of the log-cutting assemblies
30, 32, 34, 36, and 38. The linear positioners move the
log-cutting assemblies 30, 32, 34, 36, and 38, linearly
along the saw assembly rails 60 to the predetermined
positions as calculated by the scanner computer 24. As the
25 log-cutting assemblies 30, 32, 34, 36, and 38 are being
positioned, the log travels to the saw gallery 28. Once
the log arrives at the saw gallery 28, the log is delivered
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into the cradle arms 90. The teeth 100 of the cradle arms
90 prevent the log from rotating during the sawing
operation. The log-cutting assemblies 30, 32, 34, 36, and
38 have been positioned to the optimum cut locations, prior
to the log being delivered into the cradle arms 90. Once
the log has been transferred into the cradle arms 90, the
hydraulic cylinder 84, under the control of scanner
computer 24, extends to pivot the log-cutting saw blade 70
of each of the log-cutting assemblies 30, 32, 34, 36, and
1o 38 down to cut the log simultaneously at the optimum cut
locations. After the cuts have been made, the hydraulic
cylinder 96 retracts causing the cradle arms 90 to pivot
down and towards the log-cutting saw box 62 thus allowing
the cut segments of the log to fall onto the output
i5 conveyor 18. Output conveyor 18 then transports the cut
segments of the log to be processed further.
It will be appreciated by those skilled in the art
that the log merchandiser of this invention is
2o distinguished by its versatility, simplicity, and
efficiency. The transverse feed allows the log-cutting
saws to all be adjusted before the log is loaded into the
cradle arms 90, thereby avoiding the need to replace the
cradle arms 90 with a more complex system to allow the log
25 to be moved while the log is positioned on a saw bed for
cutting, as in some other systems. Moreover, the design of
the cradle precludes the need for a clamping system to hold
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the logs during sawing, a common feature of other log-
cutting systems.
The conveyors are standard, commercially available
conveyors available from a number of suppliers. These
conveyors may be of variable length and number used in
series to span the required distances. Furthermore, it
will be understood that the motors, conveyors, linear
positioners, saw blades, wheels, pivots, etc. used
1o throughout this invention may be of any desired design
according to the knowledge of those skilled in the art and
operate in conventional fashion to achieve the intended
result. Indeed, the hydraulic cylinders, including those
motivating the log-cutting saw beams and cradles, may be
s5 replaced with electric or pneumatic equipment, if so
desired.
It will also be acknowledged that any scanning or
computing system may be used to construct a preferred
2o embodiment of this invention and achieve the intended
operation. And although not described above, it should be
understood that the computing system controls the various
elements of the log merchandiser via a system of
programmable logic controllers (PLCs) or equivalent control
25 devices, and that these may also be of any appropriate
design.
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Although the present invention has been described in
detail with reference to one preferred embodiment thereof,
it will be clearly understood that this is by way of
illustration only. Many variations and alternative
embodiments of the invention will now be apparent to those
skilled in the art, and are not to be excluded from the
scope of the invention, which is to be determined only by
the appended claims, as set forth below.
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