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Publication numberUS3811487 A
Publication typeGrant
Publication dateMay 21, 1974
Filing dateOct 19, 1971
Priority dateOct 19, 1971
Also published asCA969453A, CA969453A1
Publication numberUS 3811487 A, US 3811487A, US-A-3811487, US3811487 A, US3811487A
InventorsR Brewster, L Warren
Original AssigneeR Brewster, L Warren
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automatic sawmill
US 3811487 A
In an automatic sawmill, a caliper device measures the diameter of an incoming log and the log is then positioned against a pair of backstands over a log receiving carriage. A plurality of cutting devices are positioned relative to the carriage, and the speed control for the carriage is predetermined, in response to the log diameter. The diameter measurement is supplied to data processing circuitry which provides outputs indicative of "sets" to be taken by the aforementioned backstands and cutting devices for sawing the log into a number of cants, boards, or slabs in a manner making optimum use of the log content.
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Description  (OCR text may contain errors)

United States Patent 1 Warren et al.

[111 3,811,487 May 21, 1974 [76] Inventors: Lyle D. Warren, 500 Birch St.,

Sweet Home, Oreg. 97386; Robert W. Brewster, 5924 SE. McNary Rd., Milwaukie, Oreg. 97222 [22] Filed: Oct. 19, 1971 [2]] Appl. No.: 190,589

[52] U.S. Cl. 144/312 [51] Int. Cl B27b 1/00 [58] Field of Search 144/312 [56] References Cited UNITED STATES PATENTS 3,459,246 8/1969 'Ottosson 144/312 3,304,971 2/1967 Peasf 144/312 R 1,252,445 l/l918 Johansson et al 144/312 1,393,529 10/1921 Haley 144/312 L53 L51 LSl4\ L 26\ 94 3 AUTOMATIC SAWMILL Primary Examiner-Donald R. Schran Attorney, Agent, or Firm-Klarquist, Campbell, Leigh, Hall & Whinston Sparkman,

[ 5 7 ABSTRACT ln an automatic sawmill, a caliper device measures the diameter of an incoming log and the log is then posi- I tioned against a pair of backstands over a log receiv- 6 Claims, 24 Drawing Figures EATENTEB MAY 21 I974 sum 01 0f 11 LYLE D. WARREN ROBERT W. BREWSTER INVENTORS Om @Q Qm Om m aw NmmJ MmJ BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYS PATENTEDHAY 2 1 1974- v2 v V Q9) Ilh @9 a V. x q: NmmA \09 we. g.




SHEET as D? 11 FIG. 8



cmaa CR 90. CRIOQ DD CYL- FIG. 20

ROBERT W. BREWSTER I INVENTORS BY I BUCKHORN, BLORE, KLARQUIST & SPARKMAN i l LYLE D. WARREN ATTORNEYS AUTOMATIC SAWMILL BACKGROUND OF THE INVENTION In sawmill operation, the sawing of a log is frequently accomplished in a number of stages according to the operators best estimate of log size and the number of pieces of largest size which may be advantageously obtained therefrom. Decreasing timber stands require the most efficient use of raw material, i.e. without the excessive waste heretofore occasioned, and also the desirability of providing lumber products at fairly low cost makes more efficient methods highly desirable. A more rapid and accurate system of sawing can be of particular importance in the case of smaller logs wherein a large number of logs must be handled in order to produce a reasonable output.

SUMMARY OF THE INVENTION The present invention relates to an automatic sawmill and particularly to such a sawmill and method of operating the same wherein large quantities of raw materials are handled and the output in board feet and board size produced from each log is optimized.

According to an illustrated embodiment of the present invention, a sawmill having plural cutting means and a movable carriage receives a log on the carriage for travel through the aforementioned cutting means. The log is measured and in response to such measurement a plurality of cutting instruction are produced for cutting the log into a predetermined number and size of cants, boards, or slabs, these cutting instructions being effective to bring about transverse relative movement between the position of the log and the position of the cutting means.

In accordance with the preferred embodiment, the automatic sawmill includes a data processing circuitry which accesses sets for the cutting means and/or the log in automatic response to a diameter measurement of the log. The data processing circuitry desirably includes memory means including a sawing program most advantageous for any particular diameter log within predetermined limits.

A backstand method of cutting is perferred wherein one side of the log is aligned in parallel relation to the carriage center line or carriage movement through the cutting means, thus producing cants, boards, or slabs having faces parallel to the said one side of the log. The programming of the data processing circuitry is predetermined for making an optimum number of cuts starting substantially at a datum plane parallel to and proximate the said one side of the log.

In order to secure the positioning of the log with one side parallel to the carriage center line, while also positioning the log transversely with respect to certain cutting means, plural backstand means are utilized against which the log is transported by charger means movable in transverse relation to the carriage. Separate charger means are associated with separate backstand means so that aligning can take place, with the individual charger means being arrested in their forward movement as aligning is accomplished. After the log is correctly aligned with the forward side thereof parallel to the carriage, means on the carriage engage the log for carrying the same through the sawmill, and the aforemen tioned charger means are withdrawn.

It is accordingly an object of the present invention to provide an improved method and apparatus for automatically cutting logs into one or more cants, boards, orslabs.

It is a further object of the present invention to pro vide an improved method and apparatus for cutting logs into an optimum number of pieces, representing an optimum number of board feet, in response to measurement of the log size.

It is a further object of the present invention to provide an improved method and apparatus for rapidly receiving logs, measuring the same, and in response thereto automatically selecting sawmill sets as will provide efficient utilization of the log content.

It is another object of the present invention to provide an improved method and apparatus for utilizing the measurement of a log for accessing data processing circuitry to provide the optimum position of cuts to be made in the said log.

It is another object of the present invention to provide an improved method and apparatus for charging logs onto a sawmill carriage and engaging the said logs for movement through cutting means therefor.

It is a further object of the present invention to provide an automatic sawmill having improved data processingmeans responsive to log diameter for accessing the sawmill sets suitable for cutting the log into the optimum number and size of pieces.

It is another object of the present invention to provide an improved sawmill method and apparatus wherein a log is received and aligned relative to one side of the log in parallel relation to the sawmill center line, in its optimum position for securing the maximum product output from the log.

The subject matter which we regard as ourinvention is particularly pointed out and distinctly claimed in the concluding portion of this specification. The invention, however, both as to organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings wherein like reference characters refer to like elements. 7

DRAWING FIG. 1 is an overall plan view or layout of an automated sawmill according to the present invention FIG. 2 is a vertical cross-section of the FIG. 1 sawmill taken generally along line 2-2 in FIG. 1, but also including a full end view of a caliper device,

FIG. 3 is a vertical cross-sectional view taken at 3-3 in FIG. 1,

FIG. 4 is a partial plan view taken along 4-4 in FIG. 2, illustrating charger mechanism,

FIG. 5 is a vertical cross-section also illustrating the charger mechanism and taken at 55 in FIG. 2,

FIG. 6 is a partial illustration of a caliper device as seen along line 6-6 in FIG. 3,

FIG. 7 is a cross-sectional detailed view taken generally at 7-7 in FIG. 3 illustrating guide means for a sawmill carriage dogging bar,

FIG. 8 is a vertical cross-section taken at 8-8 in FIG. 1, and illustrating movable band mill and chipper head assemblies,

FIG. 9 is a vertical cross-section taken at 9-9 in FIG. 1, illustrating an off-bearing roll portion of the sawmill,

FIG. 10 is an elevational view of a hydraulic pump for controlling sawmill carriage movement,

FIG. 11 is a vertical cross-sectional view of an alternative log charger apparatus, according to the present invention,

FIG. 12 and 12A are schematic or elementary diagrams of sequence control circuitry for the automated sawmill according to the present invention,

FIG. 13 is a block diagram of data processing circuitry, according to the present invention, adapted to provide cutting instructions in response to log measurement,

FIG. 14 is a detailed view of a first portion of the FIG. 13 coding matrix, such portion being associated with the right chipper head sets,

FIG. 15 is a schematic diagram of a similar portion associated with left chipper head sets,

FIG. 16 is a schematic diagram of yet another portion of the FIG. 13 coding matrix associated with left movable band saw sets,

FIG. 17 is a schematic diagramof another similar circuit portion for providing right movable band saw sets,

. inches, and 13 inches, respectively.

DETAILED DESCRIPTION Referring to the drawings and particularly to FIG. 1 illustrating the general layout of an automated sawmill 20 according to the present invention, such sawmill includes carriage means 26 for receiving a log from log charger means 22, wherein the charger means is disposed at susbtantially right angles to the carriage path. The carriage travels upon wheels 84, 85, and 88 in a direction advancing a log carried thereby through left and right band mill and chipper head assemblies 28 and 29, as well as through left and right band mill assemblies 30 and 32 positioned along and on either side of the .carriage path, for sawing the log.

A caliper device 24 is located adjacent the carriage and is used for measuring the diameter of the log prior to sawing, i.e. when the log is supported upon charger means 22, while a pair of backstands 106 and 108, located adjacent the carriage opposite the charger means, are employed to bring about proper alignment of the log relative to the carriage in accordance with the log diameter measurement. Data processing or computer type circuitry supplies the particular sets for the backstands, as well as chipper head and band mill positions and carriage speed for a particular log size, in such a manner as to saw the log into a number of cants, boards, and/or slabs making optimum use of the material in the log.

At the outfeed end of the chipper devices and band mills, an off-bearing roller assembly 34 is positioned for receiving the cut lumber. A sweep arm 136 removes the center cant after release thereof, toward the end of travel of the carriage.

Briefly considering operation of the mill, the caliper device 24 is remotely controlled for measuring the log diameter after the log has been delivered to the charger means 22. The measurements taken from the log are employed to address data processing circuitry which will then select the optimum positions for backstands 106, 108, as well as the optimum positions of the chipper heads and band mills. The charger apparatus carries the log forwardly until the log reaches the backstand means 106 and 108, at which time the forward movement of the charger apparatus is arrested, placing the forward side of the log in parallel relation to the center line of the mill, or parallel to the direction of subsequent travel of the log through the mill. The backstands are then automatically retracted while dogs and 101 are operated to engage the ends of the log. Such engagement initiates retraction of the charger means 22, and when the charger is out of the way the carriage 26 moves to the right at the speed also determined in accordance with the calipered log diameter. The log is now cut, and a limit switch detects the end of travel for stopping the carriage and operating sweep arm 136. When the sweep arm has operated, return movement of the carriage is initiated and the charger apparatus may deliver another log thereto. It will be noted that another log can be calipered as the preceding log is being cut. 1

Considering the invention in greater detail with particular reference to FIGS. 2, 4, and 5, as well as FIG. 1, powered feed rolls 36 initially reside in the upper or full line position in FIG. 2, for receiving a log longitudinally thereupon. Each of the feed rolls comprises a ribbed, hourglass roller rotating at the same speed as the remaining rollers for transferring the log into the mill. The power drive to the rollers is manually controlled so that rotation may be discontinued when the log is in correct position over conveyor chains 40. Then, frame 137 carrying the feed rolls is lowered by means of air cylinder 37 for placing the log upon conveyor chains 40.

Each of the conveyor chains 40 suitably comprises a pintle chain, and the chains are interleaved with the structure of charger 22 so that a log may be carried over the charger structure and delivered to charger cradles 58 and 59. The chains also interleave rolls 36 whereby a log can be deposited upon the chains from rolls 36 as hereinbefore mentioned. The center chain 40' as viewed in FIG. 2 is supported upon sprockets 138, 139, 140, and 141 journaled in bearings secured to the main frame 54 of the mill, with sprocket 138 suitably being driven by a drive shaft from motor 142. The corresponding sprockets for the remaining chains are similarly driven from the same drive shaft. Theupper chain courses are received in chain guides 144, each provided with a shelf 146 upon which the upper runs of the chains may slide. The head end sprocket is located immediately adjacent the tapered forward ends of charger beams 44 and 45 which pivotally carry log receiving cradles 58 and 59. One or more logs, e.g. as illustrated at 148, are received upon chains 40 but are prevented from initial transfer onto the charger cradles by means of air-operated pin stops 42. Thus, a plurality of logs may be disposed upon the chains 40, and the chains operated inconjunction with the pin stops for depositing one log at a time upon the cradles 58 and 59. As the pin stops 42 are dropped, and the conveyor chains energized, a log can be moved off the head end conveyor sprockets and along the tapered forward edges 150 of charger beams 44 and 45, onto the aforementioned cradles.

Each cradle comprises a steel plate horizontally piv oted between the sides of one of the charger beams. The cradles are respectively provided with control arms 152 operated by means of air cylinders 60 trunnion supported from the respective charger beams. The air cylinders 60 are adapted for positioning the cradles 58 and 59 either in a substantially horizontal position, or in the uptilted position as illustrated in FIG. 2, for catching a log delivered thereto.

The charger beams 44 and 45 are characterized by a box-like construction and are internally provided with longitudinal rods 46 which are slideable within cylindrical openings 'in upright supports 48. Hydraulic cylinders 56 and 57 extend through the upright supports 48 and are supported thereupon, while operating rods therefor are connected to brackets 154 depending from the charger beams. As thus appears, the charger beams are slideable with respect to the vertical supports 48 from the position illustrated in FIG. 2 to a position to the right thereof. Actuation of hydraulic cylinders 56 and 58 enables movement of the cradles toward backstands 106 and 108, e.g. to a position which would place a log between carriage dogs 100 and 101 as illustrated in dashed lines at 156 in FIG. 2. After subsequent engagement of the log by dogs 100 and 101, the cradles may be dropped to the position illustrated in dashed lines at 158 in FIG. 2, e.g. a substantially'horizontal position, through operation of air cylinders 60 so that the charger beams may be withdrawn to the left. As hereinafter more fully indicated, the log is not in most cases centered between dogs 100 and 101, but this positioning for the cradles is merely illustrative. The charger beams are actually driven to the right until the log carried by the cradles makes full contact with fingers 110 and 111 of backstands 106 and 108, respectively, in accordance with the desired cut programing for the particular log. After contact, the movement of the charger beams towards the backstands 106 and 108 is arrested as hereinafter more fully explained.

A horizontal beam member 160 joins upright supports 48 for a given charger beam to provide a unitary structure or charger frame 50. The charger frame 50 is pivotally supported upon the main frame 54 by means of bearings 52. Each charger frame is thus independently tiltable in a direction perpendicular to the direction of charger beam movement, or substantially in the longitudinal direction of the carriage, while the charger frames are maintained in their substantially upright position employing spring suspension means including shock absorber means (not shown) so that only a limited horizontal movement is permitted. When a log is received upon charger cradles 58 and 59, and the charger beams transfer the log to a position between dogs 100 and 101, the engagement or dogging of the log can produce undesirable stresses in the cradles 58 and 59 when, for example, a knot or branch extending from the surface ofthe log catches one of the cradles 58 or 59, or part of the charger beams. For this reason the charger frames are allowed to move in the direction of the log in a limited manner. After the cradles 58 and 59 are dropped, through operation of air cylinder 60, and the charger beams are withdrawn, the charger frames return to their substantially upright position.

Referring particularly to FIGS. 2 and 3, as well as to F IG. 1, carriage 26 comprises a narrow elongated steel beam 80 having a cross member or head end member 82 welded thereto completing a T configuration. The

head member 82 of the carriage is provided with support wheels 88 which travel along flat rails 90, and a central V-shaped guide wheel 84 which travels along V-rail 86. At the opposite end of the carriage, beam is supported by a second guide wheel 85, also V- shaped, which rolls along rail 86. A long hydraulic cylinder 94 has its operating rod pivotally secured to the head end of carriage beam 80 and is adapted for propelling the carriage in a left to right direction in FIGS. 1 and 3 whereby a log carried by the carriage will be urged through the band mill assemblies 28, 29, 30, and 32. The hydraulic cylinder 94 is therefore quite elongated to provide for piston movement corresponding to desired carriage movement, with the opposite end of cylinder 94 being attached to mill framework.

The top of carriage beam 80 is provided with a machined V slot 164 (see FlG. 7) along which a dogging bar 96 slides, such bar carrying a pivotally mounted dog having hardened teeth for engaging the end of log. The dog 100 narrows towards its pivot point and is received between 'side plates 166 welded to the dogging bar. Springs 168 maintain the tooth face of the dogging bar in a substantially vertical position, but allow some pivotal movement thereof in a vertical plane when the dog engages a log. y

Secured upon beam 80 is a guide assembly 98 having a V-shaped shoe 170 for engaging the top of dogging bar 96 and maintaining the same in a vertical attitude. The shoe 170 is provided with top adjusting screws 172 provided with lock nuts and employed for the purpose of the vertically adjusting shoe, 170 so that slideable contact is provided between the shoe and the dogging bar. Since the carriage itself moves in alongitudinal direction, carrying the assembly 98 therewith, a top extension 174 is secured thereto which rides in a longitudinal guide 176 positioned along the lower side of lbeam 178 depending. from mill arches 180 above the carriage path.

An air cylinder 104 is mounted by means of trunnions 181 between supports 183 extending upwardly from the head member 82 of the carriage 26. The operating rod 182 of this air cylinder is pivotally connected to the head end of the dogging bar 96 for forcing the dogging bar to the right when a log is to be engaged, i.e., after a log is correctly positioned between dogs 100 and 101 upon cradles 58 and 59 of the charger. Dog 101 is pivotally supported upon an upright 102 welded to the right hand end of carriage beam 80 above wheel 85, and is urged to the vertical position by a pair of springs in substantially the same manner as was discussed with respect to dog 100.

The log is charged onto the carriage with respect to backstands 106 and 108 which are movable toward and away from the carriage and hence toward and away from the charger apparatus. Each backstand includes a plurality of vertically disposed log contacting fingers. Thus backstand 106 includes four log contacting fingers 110, while backstand 108 includes fourlog contacting fingers 11 1, wherein each such finger is pivoted for operating a switch 184 when contact is made with a log.

Referring to FIG. 2, backstand 106 is illustrated from the side and includes a horizontal support 186 carrying horizontal guide rods 112 upon which horizontal guides 188 slide. A plate 190 attached to guides 188 carries switch 184 and a pivot arm 192 at the forward end thereof to which fingers 110 are pivotally secured.

Each of the fingers has an L-shape to provide the downwardly extending log contacting portion as well as a horizontally extending lever arm for operating a switch 184. The fingers are formed of relatively flexible material which will bend somewhat with the elastic limit for actuating a switch 184 without becoming damaged by log contact. As will hereinafter more fully appear,'a plurality of fingers with a corresponding plurality of switches are utilized for each backstand in such a manner that all of the switches in a backstand must be operated before charger movement is arrested. This cooperation of the backstand fingers provides a true indication of the side of the log presented thereto, while ignoring knots or small protrusions which might give an incorrect indication of the log side if only one backstand finger were to be employed.

Also associated with each backstand is a setworks numbered 114 in the case of backstand 106, and numbered 116 in the instance of backstand 108. Each such setworks comprises a plurality of air cylinders disposed in serial fashion whereby the total movement produced equals the totaloperatingrod extension or movement of the individual cylinders. Thus, each cylinder is provided with one or two operating rods which are connected to the operating rod or cylinder next in line. Each cylinder is double acting in response to a pneumatic control (not shown) for placing each cylinder in the operating-rod-in or the operating-rod-out position.

Setworks for other purposes are well known in the art and need not be described in further detail. In the instance of each backstand, the series of air cylinders 114 and 116 are supported by frames 194 and 196 respectively. Each of the setworks comprises seven cylinders having a piston throw of /8 inch, M; inch, /2 inch, 1 inch, 2 inches, 2 inches, and 4 inches, respectively. These cylinders, when actuated, are capable of providing the corresponding movements toward the'sawmill center line and combustions of these cylinders, when actuated, will be capable of moving the backstand in oneeighth inch increments towards the center line of a sawmill. When the backstand is moved to the desired position, and the charger moves theretoward with a log which contacts the backstand fingers disposed at such position, actuation of the corresponding switches 184 will shut off the supply of hydraulic fluid to the hydraulic cylinder 56 or 57 of the charger so that the log will remain in position where the backstand fingers are contacted. The backstands are moved inwardly and outwardly together from a common reference line parallel to the center line of carriage beam 80, and hence the forward side of the log will be parallel to the center line of the sawmill carriage beam 80.

It should be emphasized that the two charger mechanisms operate substantially independently from one another for accomplishing placement of the forward side of the log in parallel relation to the center line of the sawmill. For this reason, each charger beam has associated therewith one of the backstands directly opposite thereto which controls the charger movement. Thus, charger beam 44 and cradle 58 are substantially opposite backstand 106, while charger beam 45 and cradle 59 are substantially opposite backstand108. Before movement of the charger bearing a log toward the carriage, both backstands 106 and 108 are moved towards the carriage by a like amount whereby fingers 110 and 1 11 are disposed in parallel relation to the carriage. The log, however, will generally be tapered and consequently the larger diameter end of the log will ordinarily contact backstand fingers before the smaller diameter end of the log. 1n the instance of the specific v embodiments illustrated, barked logs were cut eight feet long and generally. disposed (by means not shown) with the smaller end in cradle 59. Then, when charger cylinders 56 and 57 are actuated, and the log is moved forwardly, fingers of backstand 106 will be reached by the log before fingers 111 of backstand 108. It is realized this need not be the case if different amounts of hydraulic fluid are provided to the cylinders, but this example is employed for purposes of illustration. When backstand fingers 110 operate their corresponding switches, hydraulic cylinder 56 is stopped. A short time later'when the smaller end of the log contacts fingers 1 ll, movement of hydraulic cylinder 57 is similarly arrested, placing the forward side of the log (that is the side towards the backstand) in parallel relation to the mill center line. It is understood the same end result ob- 1 tains if the charger cylinders do not move at the same rate and if, for example, the smaller end of thelog were to reach the corresponding backstand first.

The carriage during loading is substantially stationary and at the left hand extremity of its travel path, but after the log is dogged by operation of air cylinder 104, producing engagement of the log between dogs 100 and 101, the carriage is moved tothe right for carrying the log through band mill and chipper head assemblies 28 and 29, as well as band mills 30 and 32, wherein the log is cut into the desired number of pieces. Considering first the band mill and chipper head assemblies 28 and 29, as illustrated in FIGS. 3 and 8, as well as FIG. 1, each said assembly comprises a band mill husk 198 slideable toward and away from the center line of the mill. Each husk is provided with a flat skid 200 mounted on a flat rail 202 extending in a direction perpendicular to the mill center line and supported on structure therebeneath. Parallel to skid 200, a V- shaped skid 204 is mounted upon husk 198 for cooperating with V-shaped guide rail 206. Each band mill husk carries a motor 208 adapted for driving a band saw 210 within guard 212 via a conventional driving system. The band saw is disposed in a plane parallel to the center line of the sawmill in the proper position for making the desired saw cut and is supported in a conventional manner from husk 198. The husk for assembly 28 is moved inwardly and outwardly toward the mill center line by means of a setworks similar to the setworks hereinbefore discussed but comprising a single cylinder having a 2 inch throw. Similarly, right hand assembly 29 is movable toward and away from the sawmill centerline through actuation of setworks cylinder 132 also having a two inch throw. Consequently, each band mill is movable between separate in and out positions which will be hereinafter defined in greater detail. Thus the band saws associated therewith are movable inwardly and outwardly to desired positions with respect to the mill center line.

Also supported upon each husk 198 is a chipper head 118 driven by a motor 214. These chipper heads are disposed at right angles to the center line of the mill while the motors and bearing supports therefor are each mounted upon a frame 216 slideable along nylon skids 218 upon sub support 220 of the sawmill husk 198. Thus, the chipper heads move with respect to the sawmill husk, which itself is movable inwardly and outwardly toward and away from the mill center line. The

left hand chipper head is caused to move inwardly and outwardly with respect to a supporting band mill-husk by means of setworks 120 comprising a pair of air cylinders each having a one and /8 inch throw. The right hand chipper head is movable inwardly and outwardly on its supporting sawmill husk under the control of setworks 124 comprising air cylinders respectively having a /8 inch throw, a one inch throw, and a two and inch throw.

In the present embodiment, the band mills 30 and 32 are substantially similar in construction to the movable band mills just described, and similar elements are referred to in the drawings by means of primed reference numerals. The band mills are again. located on skids as a matter of convenience for positioning the band saws relative to the mill center line in the proper cutting position, but no setworks were employed in this particular embodiment for selectively locating the band saws in different positions. Hence, band mills 30 and 32 will be referred to as fixed band mills, which, in the instance of the present embodiment, were disposed to provide a cut of a nominal two inches from the center line of the mill. Thus, in the embodiment described, a center cant is provided having-a nominal four inch thickness as the log passes between the fixed band mills 30 and 32. It is understood that carriage beam 80 and the'rail structure therebeneath for supporting the same is narrow enough to pass between band saws 210 of band mills 30 and 32. Generally speaking, the positions of the band mills and chipper heads of assemblies 28'and 29 will be at a greater distance from the mill center line in order to cut board thicknesses on either side of the center cant, except in the case of logs of smaller diameter.

In the case of the fixed band mills, the band saws are positioned on the reverse side of the band mill husk from the band mill positions on the movable assemblies. Thus, the fixed band saws are located adjacent the movable band saws, and immediately thereafter along the center line as one proceeds along the center line of the mill.

After the log has passed through both movable band mill and chipper head assemblies, as well as both fixed band mills, i.e. after dog 100 has passed between the band saws of the fixed band mills, the side boards or slabs fall upon powered rollers 222 of off-bearing roller assembly 34 by means of which the same are delivered to a right angle chain conveyor partially indicated at 224 in FIG. 1. Skirts 226 on either side of carriage beam 80 direct the boards as well as the center cant onto the off-bearing rollers. As the carriage moves to the right, deceleration thereof takes place, and dog 100 is moved away from the center cant so the center cant may also be dropped onto the off-bearing rolls. To insure removal of this center cant before the carriage moves back toward the head end of the mill, a sweep arm 136 is employed for urging the center cant or any other lumber off the carriage track. The sweep arm 136 includes a striking plate 228 located at the lower end of arms 230 pivotally supported from the mill structure for rotation about an axis parallel to the mill center line. Crank 232 secured to arms 230 is operated by air cylinder 234 secured to the mill structure, the cylinder having an operating rod 236 pivotally connected to crank 232. The operating rod 236 is normally with drawn upwardly by the cylinder so the striking plate 228 remains clear of the carriage track during carriage movement. However, when the carriage reaches its right hand position, cylinder 234 is operated for swinging the striking plate 228 across the carriage for removing any remaining wood as described; The striking plate is then upraised again and the carriage drive is reversed for returning the carriage to its position at the head end of the mill for receiving another log. The sweep arm and the off-bearing roll assembly are seen in FIG. 9 as well as in FIG. 1.

As hereinbefore mentioned, the speed of carriage travel is variable and predetermined, and moreover the direction of carriage travel is reversed after each pass through the mill so the carriage may return to a position for receiving another log. The carriage is moved along its path by means of hydraulic cylinder 94 located at the head end of the carriage'and this cylinder is driven by means of a variable displacement pump, both in the case of forward and backward movement directions for the carriage. This variable displacement pump provides hydraulic fluid at the proper rate and in the proper direction for'correctly controlling carriage movement. The variable displacement pump employed in the case of the present apparatus was a Sundstrand pump,- Model 23, manufactured by the Sundstrand Company at Rockford, Illinois, and of the type having a swash plate which moves over center to provide reversing action. This pump is illustrated at 239 in schematic form in FIG. 10. The pump is provided with a control handle 238 adapted for controlling the rate of flow and direction of flow of hydraulic fluid in lines 240 and 242 which are connected to either end of carriage drive cylinder 94 in a conventional manner. The output of the pump will be responsive to the position of control handle 238 so long as solenoid actuated dump valves 244 and 246 are closed, these valves having been added to the otherwise standard pump. When dump valves 244 and 246 are opened, hydraulic control fluid which permits control of the pump 239 by controlhandle 239 is drained to hydraulic fluid tank 248.

The pump 239 includes plural pumping cylinders which are motor driven through a rotatable swash plate the angle of which isdetermined by a pairof control cylinders, schematically illustrated at 250 and 252. These control cylinders are normally operated in response to control handle 238 in correct proportionfto position the swash plate whereby the pumping cylinders pump oil at the rate determined by the control handle 238. However, when it is desired that the pump be rendered inoperative, the hydraulic control fluid is drained as described above.

The control handle 238 is positioned by means of setworks 254 supported from framework 256 and suitably having piston movements in the ratio 4/4/3/2/1. It is understood the exact linear movement provided can be adjusted in accordance with the desired speed and the length of control handle 238. Operation of the setworks cylinders in various combinations is adapted to provide control handle positions of neutral, forward speeds of 80, I00, 120, 140, I60 and I feet per minute, and a predetermined reverse speed suitably in excess of feet per minute. i

The forward speed setting for the sawmill carriage as well as the backstand setting, and settings of the left and right chipper heads and left and right movable band mills are determined in accordance with the size of the log being sawed. For this purpose, the log is measured in diameter before it is moved toward the backstands for engagement between dogs 100 and 101. Ac-v cording to the present embodiment, a caliper device 24 is employed for measuring the diameter of the log as the log resides across cradles 58 and 59 prior to movement of said cradles toward the backstand and sawmill carriage. The caliper device 24 comprises a frame 64 formed of parallel telescoping rods 258 joined at their upper ends by cross member 260. A support arm 262 extending from beam 178 pivotally engages the cross member 260 whereby the caliper frame 64 may move upwardly and downwardly. The pivot point is substantially above and has an axis perpendicular to the pivot axis of cradles 58 and 59 therebelow whereby the frame 64 can be lowered and raised vertically with respect to a log supported by the cradles.

The frame 64 further includes cross members 268 and 270 located respectively across inner and outer sections of the telescoping rods 258 and having an extending cylinder 272 therebetween adapted to adjust the degree of rod telescoping desired. A further cross member 274 joining the outer telescoping rods is pivotally connected to the operating rod 276 of an air cylinder 62, the latter being pivoted to an overhead support post 278 joined to the beam 178. Operation of the cylinder 62 raises and lowers the frame 64 with respect to cradles 58 and 59.

Secured to cross member 270 is a plate 280 carrying a pair of bearing members 282 at ends thereof between which is journaled a threaded rod 74. Threaded rod 74 includes left hand threads 76 on the left hand side of center, and right hand threads 78 on the right hand side of center, and is rotated by means of an air motor 66, supported from the frame, via a drive chain 68. The threaded rod 74 carries first and second threaded caliper arm supports 71 and 73 having left hand and right hand threads respectively for engaging corresponding threaded parts of rods 74. Depending from caliper arm supports 71 and 73 are vertical caliper arms 70 and 72 which are adapted to engage the outside of the log. At the end of the threaded rod opposite from the air motor, a cam switch 284 is'positioned which is operated twice for each revolution of the rod 74. Thus, cam operated contacts close cam switch 284 twice for each revolution of the rod.

In operation of the caliper device, the caliper frame 64 is dropped towards a log by operation of air cylinder 62 with the caliper arm 70 and 72 in their outermost position. Air motor 66 is then started whereby threaded rod 74 turns, driving caliper arm supports 71 and 73 toward one another. When the caliper arms 70 and 72 are a little more than 16 inches apart, limit switch LS4, disposed on the caliper frame, is actuated and, thereafter, the closings of the contacts of switch 284 are counted until the caliper arms encounter the log. It can be seen that the number of switch closings are an inverse function of the log diameter. After the log has been measured, the calipering device frame is withdrawn upwardly employing air cylinder 62, and the charger beams may be moved forwardly for positioning the log in accordance with the measurement. Other calipering means and charger means can be substituted as hereinafter more fully described.

Referring now to FIG. 13, data processing circuitry is illustrated, in block diagram form, for receiving the log diameter measurement from a caliper device and providing a plurality of sets for the backstand setworks, the left and right chipper head setworks, the left and right movable band saw setworks, and the speed control setworks. An input signal Y is received from the caliper device, via control circuitry hereinafter more fully described, from switch 284 on the caliper device. This input signal consists of a pulsation for each eighth inch movement of head 71 after the same oper ates limit switch LS4. The threaded portions 76 are identical in screw lead and consequently a pulsation will be produced'for each total caliper arm relative movement of one quarter-inch. As hereinbefore mentioned, the pulsations are received after limit switch LS4 is operated at which point the caliper arms and 72 are slightly more than sixteen inches apart. Thus, if the log being calipered has adiameter of 16 inches, one output pulsation willbe produced. If on the other hand the log diameter is 1'5 and inches, two output pulsations are produced and so on, down to and including 48 pulsations fora'log diameter of 4% inches, which is, in general, the smallest diameter log acceptable to the mill embodiment disclosed herein.

The input Y is applied via a pulse shaper 290 to counting means 292 comprising a first ring counter 294 for digits 0 through 9-, and a second counter 296 for digits 0 through 4. Counter 294 suitably comprises a plurality of flip-flop stages connected in serial fashion whereby an input from pulse, shaper 292 causes transfer of an active output from one of counter output leads 300 to the next. Thus, if the counter 294 is in the zero or reset stage, the top lead of leads 300 is activated, and for each ensuing pulsation received from pulse shaper 290, the next output lead downwardly in line is activated, only one output lead being upl at any time. Register circuitry of this type is well known by those skilled in the art and need not be described as regards internal wiring. 4

The output stage of counter 292 is returned to the input stage via lead 298 completing a ring counter configuration. Thus, after nine inputs from pulse shaper 290, the bottom output lead 300 will be activated, but the next input from pulse shaper 290 will produce an output once more at the topmost output lead 300 of counter 292. At the same time, counter 296v will receive an input via lead 302 causing the active output from counter 296 to shift from the topmost output lead 304 thereof to the next output lead in order. It will be seen that the number of input pulses at terminal Y will be represented in decimal fashion by the output positions of counters 294 and 296 wherein the output of counter 296 describes the l0s digits of the total, while the output position of counter 294 describes the units digits of the output total. The output leads 300 of counter 294 are respectively connected as inputs to and-gates 308, while the output leads 3040f counter 296 are similarly connected to and-gates 309. After the total pulsations from terminal Y, inversely representative of the log diameter, have been counted, an enablinginput U will be applied via pulse shaper 306 to the series of and-gates 308 and 309 for energizing the same and providing the pulse output count at the output leads of such and-gates. At a subsequent time, the counting means 292 is reset by an input Z received via pulse shaper 10. The origins of inputs U and 2 will be hereinafter more fully described.

The outputs of and-gates 308 and 309, consisting of one output from the top l0 gates 308 and one output from the lower five gates 309, will be applied to a matrix driving circuit 312 which comprises a further plurality of and-gates 314 each having two inputs, one being connected to the output of one of the gates 308, and the other being connected to one of the outputs of gates 309. The gates 314 have their inputs connected in this manner for all numerical combinations of counter summations from 1 through 48 indicative of log diameters from l6 inches down to 4% inches, in quarter-inch increments. Thus, gate 314a receives a 1 input from the units counter 294 (via the appropriate gate 308) and a zero input from lOs counter 296, and provides an output indicated at (1) in FIG. 13, providing both its inputs are up. Gate 3l4b receives an eight input from units counter 294 and a four input from l0s counter 296 and produces an output labeled (48) in FIG. 13, if both its inputs are up. One such and-gate is employed for each numerical count from 1 through 48 whereby only one of the output leads 316 will be energized for any one log diameter.

' The output leads 316 are applied to a decoding matrix or memory matrix 318 comprising a multiplicity of diodes connecting certain cross leads for selectively energizing output leads 320 thereof in response to an input from one of the leads 316. This memory matrix selects the positions or sets" for the various movable elements in accordance with the log'size calipered. The connections are indicated for one particular log size, this input being numbered (27) representative of the number 27 from counter means 292 or 27 pulses received from pulse shaper 290. This corresponds to a measured log diameter of 9 and V2 inches. The input labeled (27) accesses the desired position or sets of the backstands, chipper heads, band saws, and the desired speed. In the particular instance of the 9 and A inch log given, the backstand set desired is 4 inches, the left hand chipper head set is 1% inches, the right hand chipper head set is 2 inches, the left hand band mill set Y but are the sets relative to a zero set starting position.

in the case of chipper heads, a zero set corresponds to a position of the chipper head 1% inches from the sawresponds to band saw positions 3% inches from the sawmill center line. it will be understood that corresponding combinations of diodes in the matrix are disposed between each of the 48 input leads 316 and ones of the 34 output leads 320 in accordance with the desired program stored by the memory matrix 318.

Memory matrix 318 may comprise one or a plurality of wired diode boards for providing the desired connections, and may be termed a read-only-memory. Alternatively, a commercially available read-only-memory may be utilized wherein diode connections, transistor connections, or the like are provided therefor in an initial programming step, thereby enabling desired connections or alternatively disabling non-desired connections in accordance with a predetermined program. The program stored according to the present memory matrix is hereinafter more fully discussed.

The output leads 320 of memory matrix 318 are applied via driver means 324 to a coding matrix 326. The driver means 324 receives the six energized outputs from memory matrix 318 via ones of leads 320, according to the combination of sets prescribed, and applies corresponding drive on 34 corresponding leads 328 forming the input to the coding matrix. Thus, driver means 324 may comprise 34 relays wherein each of the leads 320 is connected to an operating coil for closing a contact delivering a voltage V to the coding matrix. Corresponding, in-line output leads are thereby energized.

The coding matrix converts the sets provided as outputs from matrix 318 to the actual setworks air cylinder combinations operated in order to secure those sets. Thus, the coding matrix drives 31 solenoids 328 for solenoid actuated valves, which in turn provide air pressure to correct ends of setworks cylinders associated ,with the backstands, left and right chipper heads, left and right movable band saws, and the speed control.

As indicated in the drawing, 16 of the inputs to coding matrix 326 relate to separate backstand sets or positions, three'are left chipper head sets or positions, five are right chipper head sets or'positions, two are left movable band saw sets or positions, two are right movable band saw sets or positions, and six are carriage mill center line, while a zero set for the band mills cormatrix 326 associated with the right chipper head posi tions, it will be seen that the input set leads (from matrix 318 via driver means 324) for right chipper head sets of zero, 1 inch, 1% inches, 2% inches, and 3% inches, are connected via diodes'330 for providing movements in'the operation of the setwork cylinders positioned by means of valve solenoids 328a. These particular setworks cylinders are numbered 124 in the foregoing drawings. Respective valve solenoids 328a position the 1 inch cylinder respectively out and back, the seven-eighths inch cylinder respectively out and back, and the 2% inchcylinder respectively out and back. The actual air valve connection is not .shown, being well understood by those skilled in the art.

Considering operation of the FIG. 14 circuit, it will be seen that 'a zero set input will cause diodes connected to the zero set input lead to conduct for placing all three cylinders of setworks 124 in the out position, or that position which locates the chipper'head nearest the center line of the sawmill. This position will be used as a basis and is 1% inches from the center line of the mill. it will be further seen that if the 1' inch input is energized, diodes will be activated for operating the seven-eighths inch cylinder and the 2% inch cylinder in the out position, but the l inch cylinder will be operated in the back" position thereby providing a 1 inch set relative to the zero set position. Furthermore, a 1% inch input causes conduction in diodes connected to the 1 inch cylinder back solenoid, the seveneighths inch cylinder back solenoid, and the 2% cylinder "out solenoid, therefore resulting in a 1% inch retraction from the zero position. The 2% as well as the 3% inch inputs likewise energize the valve solenoids 328a in combination for providing the designated set.

Referring now to FIG. 15, illustrating another portion of coding matrix 326, here designated 326b, it is seen that the three inputs are applied, via various diodes 332, to out and back valve solenoids for operating I setworks cylinders 120 in the manner identified. The inputs supplied to the top of matrix portion 326a relate to the various sets to which it is desired to position the right chipper head. Each one of these leads is a different output of memory matrix 318 derived via driver means 324. The cylinders comprising setworks 120 are operated according to the activation of solenoids 328b. Each of the setworks cylinders has a stroke of 1 /8 inches, providing a total of 3% inches when both are in the out position. When the zero set input is applied, diodes energize both out valve solenoids causing both cylinders to assume their extended condition placing the left chipper head closest to the center line of the mill. This position is the basic position, We inches from the mill center line. When the 1% set input is energized, the diodes connected thereto activate one of the cylinders solenoids to produce an out movement of one cylinder while the other cylinder is in a back position, thereby producing a 1 /8 set with respect to the zero basic location. When the 3% input is received, both setworks cylinders for setworks 120 are placed in a back position, withdrawing the left chipper head 3% inches from the zero set.

Referring to FIG. 16, the zero and 2-inch set inputs derived from memory matrix 318 for the left movable band saw are applied to a portion of coding matrix 326 designated 326C comprising two diodes 334 which respectively energize a 2-inch cylinder out valve solenoid and a 2-inch cylinder back valve solenoid in the case of zero and a 2-inch set input, respectively. The valve solenoids 328c are effective to cause operation of setworks cylinder 130 in the out and the back positions. It is seen this cylinder is extended for the zero set and retracted for the 2-inch set.

Substantially the same circuit configuration is employed in the case of the right movable band saw wherein valve solenoids 328d of FIG. 17 cause operation of setworks cylinder 132 in the *out" and back positions respectively. The FIG. 17 circuit includes matrix portion 326d incorporating diodes 336 connected as were diodes 334 in FIG. 16.

Referring to FIG. 18, a portion of matrix 326e is employed for energizing valve solenoids 328e utilized for positioning the individual cylinders of setworks 254 by valve action. Various of the diodes 338 connect the speed inputs derived from matrix 318 via driver means 324 to ls of the valve solenoids 328e. In the case of the 180 feet per minute input, each of the cylinders are in the back position or retracted. Thus, the handle 238 will be in the upraised position. For neutral position, on the other hand, the one unit, the three unit, and one of the four unit cylinders are in the back position while the 2-inch cylinder and the remaining four unit cylinder are in the out position. It will be seen from examination of FIG. 18 that the successively reduced speed values therebetween will energize the solenoids 328e in combination for placing the-lever'238 of FIG. 10 successively closer to the neutral location. In order to provide a reverse position, only the two unit cylinder is energized to its back location and the remaining cylinders are in their out" location, this being the maximum extension for the setworks in this particular example. As.

hereinbefore explained, the various handle positions thereby achieved will predetermine the travel speed of the carriage in one of the forward positions for travel of the carriage to the right in FIG. 1, in neutral position, or in reverse for movement to the left in FIG. 1.

The coding matrix has been described thus far in diode matrix form, but it is realized the same coding can be implemented by relay circuitry, wherein a given input for a given set energizes a relay or relays having contacts connected for energizing the proper combination of setworks cylinders for bringing about that set. Relay circuitry for operating the backstand setworks is illustrated in FIGS. 19 and 19A. The outputs derived from memory matrix 318 via driver means 324 are designated B1 through B16 and correspond to desired sets of 2 inches, 2 :4 inches, 2 inches, 2 inches, 2 inches, 2 54 inches, 2 "/8 inches, 3 inches, 3 /8 inches, 4 inches, 4 inches, 4 A. inches, 4 inches, 4 k inches, 5 "/8 inches, and 7 /8 inches. In this sequence, the smaller sets pertain to smaller logs, and the larger sets pertain to larger logs, the sets being measured from the mill center line. The circuitry of FIGS. 19 and 19A operates both the setworks 114 for backstand 106, and the setworks 116 for backstand 108. Referring particularly to FIG. 19A, the respective setworks cylinders heretofore referred to at 114 and 116 in FIG. 1 are positioned by means of valve solenoids AA, BB, CC, DD, EE, FF, and GG, which respectively cause extension to the outward position of each setworks one-eighth inch cylinder, one-fourth inch cylinder, one-half inch cylinder, 1 inch cylinder, a first 2 inch cylinder, a second 2 inch cylinder, and a 4 inch cylinder. The solenoid operated valves only in the case of the backstand setworks are suitably spring reversed such that in the absence of energization of a respective solenoid AA throughGG, the corresponding cylinder will return to a retracted or back position. Thus no back solenoid valves need be employed in the case of the backstand setworks.

The relay circuitry of FIGS. 19 and 19A. is arranged so that it is alternatively operable by means of push buttons PBl through P816, or automatically from the memory matrix via leads Bl throug'h B16. Thus, to produce a backstand set for each of the backstands 106' and 108 of 2 A; inches, push button PBl may be depressed. Each of the push buttons comprises a spring loaded single pole, double throw switch, where the movable contact normally makes connection with the left hand fixed contact as illustrated.

Let us assume, for example, that push button P815 is depressed. A circuit is completed through the normally closed contacts of push buttons PBl through P814 and terminals P, Q (connected by normally I closed contacts not shown in this figure). to a 24 volt d.c. source, which PBIS then connects through a diode 340 to operating coil CRl5.'Relay coil CRIS closes contacts CRlSa, CRlSb and CRlSc in FIG. 19A. Consequently, the solenoids AA, FF and GG will. be connected to the 1 15 volt a.c. source, actuating the same to the out position for controlling setworks 114 and 116. The total set will consequently be the sum of one-eighth inch, 2 inches, and 4 inches, providing a total of 6 4 inches. I

Depression of push button PBlS is arranged to produce a set" of 5 /8 inches from the sawmill center line. However, the condition of the setworks 114 and 116 with all cylinders retracted corresponds to a set of 12 inches and, consequently, to produce a 5 "/8 inch set, setworks cylinders must be energized providing a total stroke of 6 "/sinches, or twelve minus 5 Va.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3960041 *Jan 21, 1974Jun 1, 1976Warren Lyle DAutomatic sawmill
US4186310 *Jun 19, 1978Jan 29, 1980Maxey Carl WAutomatic wane detector
US4196648 *Aug 7, 1978Apr 8, 1980Seneca Sawmill Company, Inc.Automatic sawmill apparatus
US4298043 *Apr 28, 1980Nov 3, 1981H. Jack Flanders Co.Log transport system
US4333373 *Sep 30, 1980Jun 8, 1982Weyerhaeuser CompanyPositioning and feed system for cants and boards
US6463402 *Mar 6, 2000Oct 8, 2002Ralph W. BennettInfeed log scanning for lumber optimization
US6865973 *Mar 28, 1997Mar 15, 2005Amada Company, LimitedMethod and apparatus for feeding workpiece
EP0029256A2 *Nov 25, 1980May 27, 1981Kurt FeylerProcess for producing board-lamellae from round-wood
U.S. Classification144/357
International ClassificationB27B31/00, B27B29/10, B27B13/00, B27B1/00, B27B29/08, B27B31/08
Cooperative ClassificationB27B29/08, B27B29/10, B27B31/00, B27B13/00, B27B31/08, B27B1/00
European ClassificationB27B31/08, B27B29/08, B27B29/10, B27B1/00, B27B31/00, B27B13/00
Legal Events
Oct 10, 1984AS04License
Effective date: 19820303
Oct 10, 1984ASAssignment
Effective date: 19820303