US3442310A - Guiding a log through the cutter heads and saws of a profile mill - Google Patents

Description

May 6, 1969 A. MITTEN ETAL 3,442,310 GUIDING A LOG THROUGH THE CUTTER HEADS AND SAWS Filed Dec. 28. 1966 OF A PROFILE MILL Sheet rg LEONARD A. MITTEN ROBERT E. CHAPMAN myzyrons ATTORNEY9 May 6, 1969 L. A. MlTTEN ETAL 3,442,310 GUIDING A LOG THROUGH THE CUTTER HEADS AND SAWS OF A PROFILE MILL Filed Dec. 28. 1966 N MA J WM T AR NE OB E0 LR {NVENTORS ATTORNEYS p} United States Patent 3,442,310 GUIDING A LOG THROUGH THE CUTTER HEADS AND SAWS OF A PROFILE MILL Leonard A. Mitten and Robert E. Chapman, Vancouver, British Columbia, Canada, assiguors to Ernest E. Ruunion, Shelton, Wash.

Filed Dec. 28, 1966, Ser. No. 605,439 Int. Cl. B27c U08, U14; 1327b 1/00 US. Cl. 144-312 12 Claims ABSTRACT OF THE DISCLOSURE A mill profiling a conveyed log to form guide flats upon the bottom and two sides of a log with the bottom flat complemented by shallow re-entrant reference points serving a guide function correlating the log to the side cutters while the side flats are taking shape upon the leading end of the log, and with the side cutters having a downward thrust component to seat the advancing log, and having an advanced conveyor system.

Background of the invention In the sense that the present mill cuts, in the form of pulp chips, segments of a conveyed log first from the bottom and then from the two opposite sides of the log so that the chords of the segments each form a respective flat with those on the sides located normal to the bottom flat, and later sawing the produced cant on planes paralleling the side flats to divide the cant into dimensional lumber, the present invention follows the general teachings of Patent No. 3,259,157, issued July 5, 1966, to Ernest E. Runnion. Throughout the side-profiling action, i.e. the chipping of the segments from the flanks of the advancing log, it is important that the log be held against any deviation from a prescribed linear travel; and in order to accomplish this end it is the prevailing practice to employ the side flats as guide faces by having the same wipe along planar cheek plates, or fences as they are commonly termed, and this wiping action is made to occurs as soon as the flats take shape. There is, however, the problem of guiding the log during the initial period in which the log must travel before the side flats can take shape on the leading end of the log. Unless the log is held against lateral movement at the very inception of its side-profiling travel, the thrust component passed from the side cutter heads into the log causes a lateral deviation which can be rather substantial. It has been frequently necessary, on the boards sawed from each side of the profiled cant when reducing the same to dimensional lumber, to later cut away a foot or more from an end before the same can be marketed as #1 or #2 lumber.

In my prior application Ser. No. 507,111, filed Nov. 10, 1965, and now Patent No. 3,313,329, the problem was answered at least in part through the expedient of producing in the log, coincident with the forming of the bottom flat, re-entrant notches at each end of the latter, and employing inner walls of these notches as guide faces. The notches were placed so that the planes in which the inner walls lie would coincide with the planes of the side flats, the purpose being to have the side cutter heads eradicate the notches as a step incident to profiling the sides. There is an objection to this location, and that is that it precludes the guide faces from functioning in the transverse vertical plane in which the side cutter heads are cutting.

The system of my said prior application is quite satisfactory where the log being profiled has a diameter no larger, say, than 6". With logs of larger diameter the profiling is better accomplished where side flats wipe against fences having a substantial height. This the present invention accomplishes while also retaining an initial positioning function comparable to that provided by the notches. A further accomplishment of the present invention is to provide a profile mill which functions to hold the bottom flat of the conveyed log firmly seated upon a guide-way without recourse to overhead pressure, thus making it unnecessary to chip a segment from the top of the log in order to produce a planar surface on which a spring-pressed roller or the like can ride. It is of course more profitable to reduce a log to lumber than pulp chips and the top segment in a large-size cant represents considerable lumber footage. The present invention additionally provides a perfected infeed system.

The drawings In the accompanying drawings:

FIGURES 1A and 1B are perspective views which, taken together, illustrate a log-profiling mill embodying preferred teachings of the present invention; and

FIGS. 2 through 5 are views showing cross-sections of the log at sequential stages of the cutting process.

Description of pneferred embodiment Clarity in an understanding of the invention will perhaps be advanced by considering the mill as having three stations which are successively traversed by a conveyed log. Labelling these stations as a landing station, a chipping or profiling station, and a sawing station, the procedure is one in which the log is rolled to the landing station and is conveyed therefrom endwise to its length through the other two stations. There are two conveyors. One is an infeed conveyor and has as its function to move the log from the landing station into the profiling station. The other is a main conveyor and without interrupting the logs travel takes over from the infeed conveyor after the leading end of the log has progressed through the profiling station. A bottom cutter head and two side cutter heads occupy the profiling station, their function being to profile the bottom and the two sides of the advancing log. The bottom profiling is performed in advance of the side profiling. Both cutter heads rotate in a climb-cut direction, namely so as to cut in the direction of the logs travel.

The bottom cutter head 10 rotates about a stationary axis and is a stepped structure so that it removes from the advancing log a segment and two notches. The chord of the segment produces a downwardly facing flat a which lies normal to the vertical diameter of the log. The notches are let in from the flat, being spaced equidistantly from opposite sides of said diameter and formed so that each notch presents an inner wall b paralleling such diameter. The span between the inner walls is less than the width across the narrowest cant which is to be produced in the mill. In substantially the same manner shown and described in my pending application Ser. No. 507,111, .filed Nov. 10, 1965, the bottom flat and said inner walls of the notches, as soon as the same take shape, act as guide surfaces to sustain the log and hold the same against deviation from its prescribed linear travel path as the following part of the log traverses the profiling station. The guide surfaces bear upon a channel-shaped stationary guide shoe having its floor 11 occupying a plane coinciding with the cutting plane of the median knives of the cutter head and its side walls 12 each occupying a plane coinciding, other than for wiping tolerance, with the plane occupied by a respective one of the two inner walls [1 of the produced notches. Said floor portion of the guide shoe sustains the log throughout the logs conveyed travel.

The inner wall b of the notches are essentially reference points correlating the axial line of the log to the cutting planes occupied by the knives of the side cutter heads, denoted by 13. They have wiping contact with the walls 12 at least for the interval necessary for flats c to take shape upon the two sides of the log, i.e. until the leading end of the advancing log has progressed a moderate distance beyond the side cutter heads. Such side flats c are located normal to the bottom flat.

The side cutter heads are of the type shown and described in my pending patent application filed Aug. 8, 1966, Ser. No. 571,062, now Patent No. 3,346,028, wherein the axis of rotation is tilted forwardly (in this instance approximately 30, desirably) from a transverse plane perpendicular to the logs axis. In consequence of this angling, the thrust component of the climb-cutting side heads is downward and thus holds the log seated upon the floor 11 of the guide shoe.

Once the side flats take shape the same are enabled to take over from the reference points, i.e. the inner walls of the notches, as guide surfaces to work in complement with the bottom flat. In their performance of this guide ilillCtlOll the side flats wipe respective planar guide fences The main conveyor comprises live knurled rollers which engage the side flats c of the profiled log, the rollers occupying positions immediately beyond the guide fences. Both the fences and the feed rollers may be and desirably are in plural sets. The side cutter heads 13 and at least the first following set of fences 14 and feed rollers 15 receive support from two carriages 16, one at each of the two sides of the profiling station which are journaled upon rails 17 for opposing inward and outward slide movement in concert. The carriages are shifted by power, pressure-air being suitable. The movement is to a selected one of several predetermined positions, and accommodates the mill to logs of different diameter, being performed when each of a succession of logs reaches the landing station, either through manual operation of a control console by an operator overlooking the landing station or automatically by the operation of a system which igcludes a diameter-sensing device.

-The infeed conveyor provides front and rear stools 18 and 19 each mounted for reciprocal movement from and to the landing station along a path centered in relation to the profiling and sawing stations. Separately powered by means such as a motor-driven gear mounted upon the underside of the related carriage and meshing a stationary rack 20, the front stool travels a comparatively short distance, say 2 ft., while the rear stool has a relatively long travel moving from the retracted position in which it is illustrated to a position, when fully advanced, proximate to the front stool. When both stools are retracted, the same occupy positions each spaced inwardly from the related side edge of a chute which extends transverse to the infeed conveyor and along which logs roll in side-byside relation to a point of discharge elevated above the conveyor, the logs dropping onto the stools one log at a time in each cycle of operation of the conveyor by the act of tripping a stop arm (not shown), located at the discharge end of the chute. As with the control of the carriages 16, the stop arm may be controlled either manually or automatically.

The stools each provide a saddle, as 21 and 22, onto which the logs drop and each has a set of opposing hinged jaws, as 23-23 and 2424, which swing inwardly to clamp the log and center the log upon the saddles. The saddles have a jack motion, moving vertically in concert with lateral adjustment of the carriages 16 into a selected one of several predetermined positions each correlated to a given one of the several carriage settings, the purpose being to raise or lower each log in the degree necessary to properly place the log relative to the plane in which the bottom cutter head cuts. Logs of small diameter require a higher setting than logs of large diameter. The saddles perforce move to their proper setting before the jaws swing inwardly to clamp the log.

The operation of the infeed conveyor is a sequential action performed automatically. After the jaws close upon 4 the log the two stools move forwardly in concert. The short travel to which the front stool admits is suflicient to advance the leading end of the log through the bottom cutter head and onto the guide shoe, at which time the front jaws 2323 open and the saddle 21 lowers so that each are clear of the log which continues to be advanced by the continuing forward travel of the rear stool 19 until the leading end of the log has traversed the side cutter heads 13, the initial set of fences 14, and come under the driving influence of the first set of feed rollers 15 which, as before stated, have a feed rate the same as the infeed conveyor. The rear saddle 22 will have lowered and the rear jaws 24-24 opened momentarily before the rear stool reaches its front limit stop and both stools now return to the rear limit of their travel, preparatory to receiving a following log as soon as the trailing end of said preceding log has completed its profiling travel and cleared the feed rollers 15. A second set of independently adjustable feed rollers, with associated fences, can take over and convey the profiled log through the sawing station so that a second log can be deposited on the landing station and the side cutter heads with their associated first set of fences and feed rollers adjusted therefor while a previously profiled log is proceeding through the sawing station.

The sawing station which we have here elected to illustrate is one in which the sawing is performed by band saws 25. The construction and mounting details of these band saws is the subject matter of an application for patent which is now in preparation and suflice it to here say that the same divide the profiled cant into dimensional lumber. The lumber is individually edge-trimmed.

It is believed that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my invention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits,

We claim:

1. The method of profiling a log, comprising first conveying the log by an infeed conveyor in a direction endwise to its axis along a linear travel path, at a first cutting station located so as to be traversed by at least a front portion of said log while conveyed by said infeed conveyor cutting from the bottom side of the log a portion which includes a segment and two shallow notches, the chord of the segment forming a flat upon the underside of the log and the two notches being let in from the flat to each provide a respective one of two outwardly facing guide walls which parallel the logs vertical diameter and are spaced equidistantly from opposite sides thereof, as soon as said bottom flat and the guide walls take shape employing the same as guide surfaces for guiding the log through at least a portion of the travel path which lies beyond said first station, at a second cutting station located so as to be traversed by the leading end of the log while so guided and while a substantial portion of the log has yet to clear the first cutting station cutting from each of the two flanking sides of the log a respective segmental portion the chords of which form flats which parallel the logs vertical diameter and are spaced therefrom equal distances exceeding that of said guide walls, as soon as said flank-side flats take shape employing the same as guide surfaces to hold the log against deviation from its prescribed travel path as the cutting action is continued upon the following part of the conveyed log, and when the leading end of the conveyed log has advanced beyond the second cutting station but the trailing end has yet to reach the first cutting staion bringing said flank-side flats under the driving influence of a set of side feed rollers having a rate of feed the same as the infeed conveyor.

2. The method of claim 1 in which the cutting at the second cutting station is performed by cutter heads having a climb-cut action and rotating about axes tilted forwardly from a transverse plane perpendicular to the path travelled by the conveyed log, consequently exerting a downward thrust moment upon the conveyed log.

3. The method of claim 1 and the step, performed as the guided log proceeds beyond the feed rollers, of progressively dividing the profiled log into lumber by the operation of band saws having their cutting planes paralleling said flank-side flats of the log.

4. The method of claim 1 in which the infeed conveyor moves in repeating cycles of reciprocal travel, receiving the logs at a retracted limit of saidtravel and transferring the drive to the feed rollers momentarily before reaching an advanced limit of said travel.

5. A profile mill comprising, in combination: conveyor means for conveying a succession of logs along an established linear travel path, a bottom cutter head occupying a first cutting station traversed by the conveyed log and acting to cut in the form of pulp chips from the bottom of the log a segment and two shallow notches with the notches being let in from a flat which the chord of the segment produces upon the log, inner walls of the notches paralleling a vertical diameter of the log and being spaced equidistantly from opposite sides of said diameter, a guideway engaged by the conveyed log as soon as the bottom flat and said notches take shape and formed to provide a bottom wall on which the flat seats and side walls wiped by the inner walls of the notches, two side cutter heads occupying a second cutting station traversed by the conveyed log as it travels a path prescribed by the guideway and acting to cut in the form of pulp chips from the opposite side flanks of the log a respective one of two segments the chords of which are spaced equally from said vertical diameter of the log and produce flats which parallel said diameter and are separated a distance substantially greater than the span between said inner walls of the notches, and a set of guide fences placed so as to be wiped by the side flats of the conveyed log as soon as the side flats take shape.

6. A profile mill according to claim 5 in which the conveyor means comprises an infeed conveyor responsible for the travel of the log until the leading end has progressed beyond the fences, and a main conveyor which then takes over from the infeed conveyor, said main conveyor comprising live feed rollers which take a driving purchase'upon the flank-side flats of the log and have a feed rate the same as the infeed conveyor.

7. A profile mill according to claim 6 in which the infeed conveyor is comprised of front and rear stools to which respective ends of the log are clamped and which each move in repeating cycles of separate reciprocal travel, receiving the logs at a retracted limit of said travel and being each disengaged from the log momentarily before reaching an advanced limit of said reciprocal travels, the front stool having a short travel while the rear stool has a long travel with both moving at the same speed and in concert during an initial stage of the rear stools advance travel.

8. A profile mill according to claim 5 in which the side cutter heads rotate in a climb-cut direction about axes tilted forwardly from a transverse plane perpendicular to the path travelled by the conveyed log, consequently holding the log seated upon said floor of the guide-Way by exerting a downward thrust moment upon the log.

9. A profile mill according to claim 5 in which said linear path travelled by the conveyed log includes a sawing station located beyond the cutting stations and occupied by band saws which act to saw the log on planes paralleling the flank-side flats and by said sawing divide the log into lumber.

10. A profile mill according to claim 6 in which the side cutter heads, the guide fences, and the feed rollers are mounted for inward and outward movement in concert into a selected one of several laterally adjusted positions each correlated to a given range of log diameters.

11. A profile mill according to claim 5 in which the conveyor means comprises an infeed conveyor responsible for the travel of the log until the leading end has at least reached the guideway, and a main conveyor which then takes over from the infeed conveyor, said infeed conveyor being comprised of front and rear stools to which respective ends of the log are clamped and which each move at the same speed in repeating cycles of reciprocal travel, receiving the logs at a retracted limit of said travel and being each disengaged from the log momentarily before the respective stool reaches an advanced limit of its reciprocal travel, the front stool having a short travel while the rear stool has a long travel with both moving in concert during an initial stage of the rear stools advance travel.

12. A profile mill according to claim 11 in which the stools each provide a saddle element on which the lcg rests and which are each mounted for movement into a selected one of at least two vertically adjusted positions each correlated to a given range of log diameters.

References Cited UNITED STATES PATENTS 3,259,157 7/1966 Runnion 144-3l2 3,313,329 4/1967 Mitten 144-312 3,344,826 10/1967 Mitten 144-312 GERALD A. DOST, Primary Examiner.

US. Cl. X.R. 144-3, 117, 174

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