CA1189766A - Diametrical log sizer - Google Patents

Abstract

ABSTRACT

A cutter, for a log sizer having a ring-shaped rotor through which logs to be sized are passed longitudinally, comprises a ring-shaped supporting disk which is fastened to the input side of the rotor. The disk has affixed thereto, in a circumferentially spaced relationship on the plane of the disc facing the approaching logs, a plurality of roughing knives and finishing knives the finishing knives being affixed in closer axial proximity to the plane of the disk than the roughing knives.

Description

3'761Ei 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.
~5 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 7~;~

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 preferred 0 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 76 Ei 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.

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.

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A cutter for a log sizer having a ring-shaped rotor through which logs to be sized are passed longitudinally, the cutter comprising a ring-shaped supporting disk to be fastened to the input side of said rotor, said disk having affixed thereto, in a circumferentially spaced relationship on the plane of said disk facing the approaching logs which are to be sized, a plurality of roughing knives and a plurality of finishing knives extending toward the center of said disk, said finishing knives being affixed in closer axial proximity to said plane than said roughing knives.

2. The cutter of claim 1, wherein a pair of said roughing knives are affixed at opposite sides of said center of said disk.

3. The cutter of claim 2, wherein a pair of said finishing knives are affixed at opposite sides of said center of said disk, such that each of said finishing knives is equidistantly spaced from each of said pair of said finishing knives.

4. The cutter of claim 1, wherein the cutting edges of said roughing knives are outside the periphery of said centre and the cutting edges of said finishing knives are inside the periphery of said centre.

5. The cutter of claim 1, wherein said roughing knives remove a portion of material from a log to be sized so as to approximately obtain the required diameter for said log and said finishing knives remove a smaller portion of material from said log so as to produce a smooth finish for said log.

6. A log sizer having a ring-shaped rotor comprising a cutter as claimed in claim 1, and further comprising:
frame means for mounting said rotor;

means for rotating said rotor relative to said frame means; and means for gripping a log and advancing said log through said rotor.