Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF T~IE INVENTION
Naturally grown trees harvested by lumbermen for
the manufacture of wood products are of various tapers and
configurations. It is advantageous that, prior to further
processing, the entire length of the tree be made a
constant diameter.
A number of patents have been addressed to
machines which remove the outer portions of a cut tree.
United States Patent No. 2,109,414 to Deiters
et al. discloses the use of a pole trimming machine having
a rotatable casing mounted for universal and floating
mo~ement. The finishing cutters rotate about their own
a~es and bodily about the axis of a pole. The rotatable
cutter has a support mounted ~or slidable radial
adjustment ~ithin the casing and can move radially
independently oE its adjustment as it engages high and low
places on the surface of the pole.
United States Patent No. 1,943,549 to White
et al. discloses a pole peeling and shaping machine
wherein rotary cutting means are used within a rotating
casing to shape the diameter of the wood.
United States Patent No~ 3,245,443 to Shields
discloses a multi-arm debarker having a rotory tool ar~
ring with one set of debarking arms of the infeed side and
another set of debarking arms on the outfeed side.
United States Patent No. 3,536,265 to Cervenak
discloses a refuse-reducing mechanism for a log barker
which makes use of stationar~ shearing bars cooperating
with rotary shearing bars mounted on a rotary plate.
United States Patent No. 2,802,494 to Nicholson
discloses the u~e of cutters for paring log
protuberances. A plurality o~ barker tools are spaced
circumferentially about a log, and the log and barker
tools are rotated relatively and moved axially
simultaneously so as to enable the barker tools to follow
a spiral path aroung the log.
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United States Patent No. 3,842,873 to Valo
discloses a cutter head for a hole-rotor type barking
machine comprising a plane ring disc provided with a
number of mutually spaced cutter blades projecting from
the disc.
~ nited States Patent ~o. 3,552,456 to Johansson
discloses a debarking machine comprising a hollow rotor
carrying debarking tools pivotable to and from the axis of
the rotor~
United States Patent No. 4,122,877 to Smith et
al. discloses a ring type debarker in which the arm
carrying section i5 mounted for rotation on a centrally
disposed, tube-like member through which the logs pass
while being debarked.
~nited States Patent No. 3,098,512 to Kendrick
discloses a post debarking machine having a rotatable drum
with bark peeling members pivotally carried adjacent the
periphery of the drumn
United States Patent No. 3,461,931 to Wexell
discloses the use of a cutting edge operating to remove
wood from the log in the form of usable chips such to
provide a cylindrical bolt of a diameter determined by the
location of the innermost shaving edge. A hollow
frustro~conical head, mounted for rotation about a
horizontal axis, is provided with a conical inner
surface. A number of radial apertures, each having a
cutter secured thereto, are disposed in a spiral helical
path. Each of the cutters has a shaving edge parallel to
the axis of the head and a parting edge at an angle to the
shaving edge. The cutters engage and cut material from
the log at different dia~eters with the shaving edges
cutting substantially parallel to the fibers to the fibers
~f the log and the parting edges cutting across the fibers
at an angle.
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Canadian Patent ~o. 584,324 discloses an
apparatus for removing bark from logs, wherein
self-opening barking tools mounted in an annular rotating
member have a leading edge shaped and mounted so that the
leading face of the tool can descend entirely through the
bark layer.
Canadian Patent No. 701,490 discloses a bark
removing machine in which the bark cutting means include
cutting wheels supported for rotation on the inner ends of
some of the scraper blades to transversely cut away bark
stripped from the log ~y the bark scraper blades.
Canadian Patent No. 1,04~,317 discloses a rotor
barking machine comprising a hollow rotor rotably mounted
in a frame, barking members pivotally journalled on the
discharge side of the rotor and directed toward the center
of the rotor, and cutting members supported on the frame
and extending close to the plane of rotation of the
barking member fox cutting off bark strips.
The present invention permits the sizing of logs
by passing the logs longitudinally through a ring-shaped
rotor having fastened thereto a ring-shaped supporting
disk. Two sets of knives are rigidly affixed to the side
of the disk facing the approaching logs which are to be
sized. The knives enable the unit not only to debark the
log and to remove excess swelling and knots, but also to
shape the log to a constant diameter.
SUMMARY OF THE INVENTION
The present invention relates to a cutter for a
log sizer have a ring-shaped rotor through which logs to
be sized are passed longitudinally, the cutter comprising
a ri~g-shaped supporting disc to be fastened to the input
side of the rotor, the disk having attached thereto, in a
circumferentially spaced relationship on the plane of the
disc facing the approaching logs which are to be sized, a
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plurality of r~ughing knives and a plurality of finishing
knives extending toward the centre of the disk, the
finishing knives being affixed in closer axial proximity
to the plane than the roughing knives.
The present invention also relates to a log sizer
comprising the above cutter, and further comprising frame
means for mounting the rotor, means for rotating the rotor
relative to the ~rame means, and means for gripping a log
and advancing the log through the rotor~
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a side view of the log sizer,
depicting a log being moved in a longitudinal path through
the log sizer.
Figure 2 is a schematic view of the log sizer,
depicting the use of a steel sizing tube in the
longitudinally extending passage of the housing unit or
the log sizer.
Figure 3 is a view of the infeed side o~ the
ring-shaped supporting disc, depicting a preferred0 arrangement of roughing and ~inishing knivesO
DE~AILED DISCLOSURE
The preferred embodiment of the invention will
now be described in detail.
The log sizer shown generally at 1 includes a
cylindrical housing unit 10 having longitudinally
extending circular passage 11 in a substantially
horizontal position therein. Passage 11 is of sufficient
diameter to permit logs to be fed into the infeed end
thereof and to be discharged from an outfeed end thereof.
Passage 11 is provided with a non-smooth relief along its
longitudinally extending walls, in order to reduce the
heat build-up which occurs because oE frictional contact
between log 2 and the walls of passage 11. Housing unit
13 is fixedly secured at the bottom thereof to supporting
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frame 12. Hole rotor 8 is rotatably supported within
housing unit 10 by means of precision ball bearings (not
s'nown). Ring-shaped supporting disk 14 is fastened to
hole rotor 8, by means of bolts 9, on the side of hole
rotor 8 facing the approaching log to be sized. Rotation
is imparted to rotor 8, and thus to supporting disk 14, by
means of belts 16 driven by an external motor. The heat
build-up within housing unit 10 is removed by an oil
heat-removing system, the oil being circulated by pump and
radiator mechanism 17.
Ring-shaped supporting disk 14 supports, on the
input side facing the approaching logs which are to be
sized, four knife holders 20, 21, 22 and 23 spaced
equidistantly about supporting disk 14 and affixed thereto
by cap screws 15. Knives 24 and 25, located on either
side of center 18 in holders 20 and 22, are roughing
knives designed to remove a majority of the material from
log 2 so as to approximately obtain the required diameter
for log 2. The inner cutting edges of roughing knives 24
and 25 are located at a distance outside the periphery of
centre 18 and thus outside the required diameter of the
log, and are aligned with imaginary chord lines 50 and 51,
respectively, of supporting disk 14. The ends of the
cutting edges of roughing knives 24 and 25 are aligned
with imaginary center line 53, perpendicular to both
imaginary chord lines 50 and 51. Finishing knives 26 and
27 are dasigned to produce a smooth finish for log 2, and
are located on opposite sides of center 18 of annular disk
plate 14, in holders 21 and 23. The cutting edges of
finishing knives 26 and 27 are located at the diameter
required for the siæed log, and are slightly inside the
periphery of center 18. The leading edges of holders 21
and 23 are aligned with imaginary chord lines 54 and 55,
respectively, of supporting disk 14, while the ends of
holders 21 and 23 are aligned with imaginary center line
56 perpendicular to both imaginary chord lines 54 and 55.
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Roughing knives 24 and 25 and finishing knives 26
and 27 are each bolted to, respectively, knife holders 20,
21, 22 and 23, by means of studs 35 attached through
elongate slots 37 of knives 24, 25, 26 and 27.
Housing unit 10 i5 provided with an intake or
feeding mechanism 28, having four toothed infeed rollers
29 which grip log 2. Use of toothed infeed rollers 29
enables log 2 to be firmly held through housing unit 10
and prevents log 2 from rotating when it encounters
rotating supporting disk 14. An outlet or discharge
mechanism 30 having four rubber outfeed rollers 31 is used
to carry log 2 through housing unit 10 after the leading
end of log 2 has passed through housing unit 10, thus
helping to ensure that log 2 does not become jammed in
passage 11. ~he use of rubber surface rollers 31 protects
the smooth finish imparted to log 2 by the finishing
knives.
In operation, logs 2 are successively Eed into
feeding mechanism 28. The toothed infeed rollers 29
longitudinally advance logs 2 through passage 11 of
housing unit 10 and past center 18 of supportin~ disk 14.
Roughing knives 24 and 25, attached to supporting disk 14
by means of knife holders 20 and 22, engage log 2,
removing material from the outside of log 2 as log 2
passes roughing knives 24 and 25 in a nonrotating manner.
F~inishing knives ~6 and 27, attached to supporting disk 14
by means of knife holders 21 and 23, subseyuently engage
log 2 to further remove material and smooth the outside of
log 2. As the leading end of log 2 moves through hole
rotor 8, it is engaged by discharge mechanism 30. Rubber
surface rollers 31, in firm pressure engagement with log
2, continue to cause log 2 to advance. As knives 24, 25,
26 and 27 remove material from log 2, the waste chip
material falls to the lower portion of housing unit 10,
where it may be removed by any suitable conveying means.
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It is seen that any particular housing unit lO
can accommodate logs of a diameter about equal to that of
passage 11. To accommodate smaller diameters, supporting
disk 14 can be removed and longitudinally e~tending steel
sizing tube 32 inserted into passage 11. Keeper ring 34
and cap screws 36 maintain sizing tube 3~ in proper
position. Sizing tube 32 also has a non-smooth inside
diameter, so as to reduce the heat build-up which occurs
because of friction between log 2 and the walls of sizing
tube 32. Sizing tubes 32 can be nested, one inside the
other, if smaller diameter logs are to be used. A
ring-shaped supporting disk 14 appropriate to the desired
diamater is then attached to hole rotor 8. If the
suppor~ing disks are pre-set for the desired diameters,
that is, if the knife holders and knives have been
pre-adjusted for the required log size, the changeover for
differently si~ed logs need take but several minutes.
The embodiment described is an example of the
present invention. ~he invention is not limited to this
example, and there are other possible forms of
construction within the scope of the invention. In
particular, the roughing and finishing knives may be
arranged in different configurations from that herewith
depicted, and the number of knives used will vary with the
diameters of the logs which are to be processed and the
feed speeds required.
