US2659396A - Shake board resawing machine - Google Patents

Description

A. F. GLEDHILL ET AL SHAKE BOARD RESAWING MACHINE Nov. 17, 1953 3 Sheets-$heet 1 Filed May 15, 1952 IN V EN TOR.

R xx 5 lilliv a 7, 1953 A. F. GLEDHILL ET AL 2, 3

' SHAKE BOARD RESAWING MACHINE Filed May 15, 1952 3 Sheets-Sheet 2 INVENTOR. A1 V/A/ F GZEDH/LL 150M 8. ZEW/fi Nov. 17, 1953 A. F. GLEDHILL ETAL SHAKE BOARD RESAWING MACHINE 3 Sheets-Sheet 3 Filed May 15, 1952 INVENTOR. AZ VIN F GZEDH/ZL 450M e. AEW/J wwm R Patented Nov. 17, 1953 UNI-TED STATESII PATENT UFFECE SHAKE BOARD BESAWING ,MACHINE T Alvin F. Gledhill, Seattle, and Leon. R. Lewis; Kirkland, "Wash.,'-assignors to Floyd I2. Lewis and-Leon E. Lewis, doing business -as L. R. Lewis-00., Seattle,- -Wash., a partnership Application May 15, 1952, Serial No. 287,986

28 Claims (01. 143-40)- l 2 Thisinvention relates to shake board resawing' feeding themthrough the saw; hence involved a machines and is more particularly concerned with high labor cost and gave a' relatively low rate of the manufacture of shakessplit by hand or production for the amount-of labor and plantotherwise, with sawn backs. The invention-is overhead expense involvedwlt has long-been evident that a major obstacle to the full commeroial development and "realization of the potentialities oi thesplit-resawn shake accordingly herein illustratively described'by'reierence to the preferred'form thereof as applied to the manu= facture of hand-split'shakes of'thetype men'- tioned, but it will be appreciated by'those skilled in the art that various modifications and change therein may be made without departing from the underlying features involved'as set forth herein-* after and defined in the appended claims.

Tapered shakes produced by halving split Red Cedar boards or the like on a biasin a resawing operation constitute a standard commercial-product used for roofing and siding'applications and are much in demand for their-attractive rustic appearance and great durability. Often the cutting of blocks and the splitting of boards for these shakes is carried out by small operators in the'field who, because of the easy mobility of their equipment and crewa are enabled to utilize economically otherwise wasted stunipage, preserved fallen logs and stands of timber toosmall or sparse to be logged economically for'regular lumber mills. However, the cost of the final prodnot has been higher in the past than various other types of shingles on a square footage basis. This is largely attributable to therelatively large amount of manual handling involved in processing this product and the absence of specialized '5 production machinery forresawing the split" boards.

As will be appreciated by those familiar with the art, it is possible to out shakes with a definite taper entirely with the use of afroe. This is done split, asthey will then lie flatter and form more weathertight shingling than if both sides are split;

In producing this latter type of shingling, herein termed a split-resawn boards split from the blook'are halved on a bias in a resaw-operation to produce two shakes from each board. The preference for this type of shake has not beendue to any outstanding economical advantage over thetapei split type in the past,

however; in fact, they have tended to 'cost as much or more because the resawing machines used previously were of a type requiring manual handling and guidance of the shake boards in shake, nontapered has been the lack of aresaw'machine capable of resaw while held at the proper inclination and- 1 offset of their froeedges-in relation to theplaneof the saw.-- These boards sawn to length and split largely by manual-operations or the like,- are necessarily rougnand -nonunitorm, in fact,

it is preferred that they-beef nonuniform shape and dimensions. For instance-they --may=vary in thickness approximately-from of an inch-to 1% of an inch and in lengthapproximatelyfrom 23 \1 inches to 27 inches. The width of the boardsrnay also vary greatly such as from 3 or 4 inches to 14 or 15inches, or even greater in typical cases Moreover, the sides and edgesof the boards, being split,--wi1l ordinarily be rougher-uneven, and sometimes beveled insteadof being squared. Also the boards may tend to bow or possesscurvature,

either-or both-lengthwise or transversely, and-in varying degrees, Obviously these rough hewn approximately parallel-sided boards of 1 varying lengthawidth and thickness cannotbe handled, heldor sawn-by any ordinary or conventlonalau- U tomatic or semiautomatic resawing inachinery on a rapid production baslswhi-leaohieving a reasonable degree of uniformityin their functional shape-that is, tapered from theirbutts to their tips; with generally squared tips instead of being out through back of their tips to remove one o1" bothcorners.

It is accordingly a general object of the present invention to provide'a production resaw machine whichwill enable spiit resawnshakes to be man factured more rapidly and economically'than-has' heretofore been possible. A further object is a board-holding and feed mechanism for a shake" board resa machinewhich will automatically position the'boards at substantially the correct inclination and offset relative to the cutting plane of the saw regardless of the size; shape or surface configuration ofthe boards withindwide com meroially' acceptable -iimits; "and furtherywill rigidlyhold the boards in that position during" the actual sawing operation despite "saw' pressure 3 tending to tilt or slew the boards and produce a curved out. While the butt thickness of the resulting shakes will necessarily vary with the thickness of the boards, it is preferred that the tip thickness of the shakes cut in the machine be fairly uniform or constant. The invention provides a means by which the boards are held and fed in a resawing machine so as to produce shakes which on the average are of substantially uniform tip thicknes and virtually always acceptably uniwhich extend parallel to the chains to define a k lineal feed path coincident with the cutting plane of the saw, are connected to the chains and carry cooperative board holder elements. Each board is held by one end between one pair of holder elements and by its opposite end between another pair of holder elements, the two pairs comprising a carriage set, and there being a number of similar carriage sets movable necessarily along the feed path by the chains to feed boards in succession through the saw. A frictional drive conveyor comprising one or more live rolls driven at a peripherally faster rate than the speed of travel of the chains, hence of the board holder elements, advances a board impositively toward the saw until the board is arrested by a yieldable detaining stop automatically projected into the feed path just prior to the board's arrival at the point of detention. Restraining stops are movedly connected to a feed chain at respective locations therealong immediately preceding each board carriage set. Each such restraining stop prevents travel of the succeeding board past the detaining stop before the latter is moved into projected position as the board is being advanced on the live rolls toward the saw. The board, while detained by the detaining stop, is next engaged from behind by an advancing pusher gauge movedly connected to one of the carrier chains immediately behind the associated carriage set. The pusher gauge advances the board positively toward the saw and forces the detaining stop into retracted position. Thereupon the carriage set holder elements are actuated and effect gripping of the board in cutting position inclined to the plane of the saw.

The holder elements engaging each end of the board comprise a lateral board gauge offset slightly from the cutting plane on one side thereof, and opposing presser means comprising one or more cam-actuated arms pivoted to contact the opposite side of the board and press it against the locating gauge. The lateral board gauge contacting the side of the board near one end is located on the opposite side of the board from the gauge which contacts its opposite end, and the board is initially positioned in the machine by a feed-in operator, manual or automatic, so that its diagonally opposite froe edges, 1. e. the smoothest edges for locating purposes, are the ones which contact the two lateral gauges.

Elongated cams, on opposite sides of the feed path, engaged by cam followers actuating the presser arms, have control surfaces thereon which are located along the feed path so as to cause simultaneous actuation of the presser arms for gripping the board in cutting position after engagement thereof by the pusher gauge. The gripping elements hold the board firmly, but because they grip the sides of the board frictionally there might be a tendency for the board to slip lengthwise through them under saw pressure. The pusher gauge not only prevents this, but correctly locates the board lengthwise relative to the gripping elements before the latter are 2 actuated to grip a board.

Further features of the invention reside in the preferred construction of the lateral board gauge and presser arms for positionally gripping irregular boards of the type mentioned. Each lateral board has two spaced-apart board-contacting outer abutments which lie at substantially equal distances from the cutting plane corresponding approximately to the desired thickness of the sawn shake tips. Intermediate these abutments is a third abutment which lies at a somewhat greater distance from the cutting plane. The purpose and advantage of having the intermediate abutment spaced farther from the cutting plane than the first named abutments of the locating gauge, lies in the minimizing of tilt of wide boards, i. e., those which, when supported by a live roll, span fully between the outer abutments, which have outward curvature or a hump on their sides contacting the intermediate abutment. But for the setback of the intermediate abutment this type of irregularity on a wide board could cause considerable tilting or offset of one edge relative to the cutting plane, and result in sawing an oblique-tipped reject shake. On the other hand, anarrow board, 1. e., one of a width, when riding on a live roll, insufilcient to cause it to span the full distance between the first-named abutments, contacts only the intermediate abutment and the outer abutment adjacent the live roll. This imparts a slight lateral tilt to a narrow board having a substantial- 1y flat side pressed against such abutments. The amount of tilt of the narrow board is not sumcient, however, to result in cutting of an oblique tip on the shake. Slight but unobjectionable tilting of narrow boards gripped in cutting position is therefore tolerated for the sake of preventing exaggerated or excessive tilting of wide boards misshapen in the way mentioned.

A further feature of the invention resides in the provision of a board supporting roll extending transversely to the cutting plane at a location adjacent the saw, which roll has sharp peripheral projections thereon which bite into the board under pressure of the saw. These projections prevent lateral skidding or slewing of a board having a, beveled edge supported on such guide roll during cutting and subjected to a torque due to the noncoincidence of the cutting plane and the line or point of contact of the board's edge with the roll.

These and other features, objects and advantages of the invention including certain details of construction of the preferred embodiment thereof as herein illustrated will become more fully evident from the following description by reference to the accompanying drawings.

Figure 1 is a plan View or the machine omitting certain parts for clarity of illustration, as adapted for use with a band saw having its cutting stretch or side, shown in. cross section, disposed vertically.

Figure 2 is a corresponding simplified. sectional side elevation view taken on line 22 in Figure 1. .J ire S (Fibeet l) is a simplified plan view of machine at further reduced scale illustrating operation thereof with shake boards at different positions advanced along the feed path hiclextends through the saw.

Figure (Sheet 3) is an enlarged fragmentary plan view with certain parts broken away or omitted for clarity illustrating various details of construction especially with respect to the board-holding elements and their relationship to the cutting plane.

Figure 5 is a corresponding transverse sectional View taken on line 5-5 in Figure 4.

Figure 6 (Sheet 2) is a partial transverse sectional view taken on line E-'6 in Figure 4, illustrating the action of the gripping elements for holding a relatively narrow shake board in cutposition while being advanced through the saw.

Figure '7 is a similar view wherein a wide shake of a certain type or shape is being similarly held in cutting position.

Figure 8 (Sheet 3) is a sectional plan view showing details of a presser device mechanism by ich. the presser arms are projected and retracted relative to the boards.

In its illustrated form, the machine generally comprises board-holding and feed mechanism by which the approximately parallel-sided split shake boards delivered to it either manually or by suitable mechanical delivery means F, not illustrated in detail herein, are fed in rapid succession endwise along the cutting plane CP (Figs. l and 7) and through the saw. In the example, saw is a band saw S and for simplicity, only a portion of its cutting stretch or side is illustrated, this being disposed vertically and thereby establishing a vertical cutting plane along which the boards are fed in a substantially horizontal lineal path. In the preferred form of the machine a high rate of production is achieved, with the saw S almost constantly active, by employing a plurality of board-gripping element carriage sets connected in series arrangement to endless carrier members which extend in circuitous paths parallel to and along opposite sides of the cutting plane. At the input end of the machine (right in Figures 1, 2 and 3) boards are placed in the respective carriage sets as each commences its travel, following those preceding it, along the upper chain stretches defining the horizontal path. Before reaching the saw, the upright, endwise-advancing board is auto matically positioned by the gripping elements to dispose th sides of the board at a horizontal angle to the cutting plane or direction of feed. After passing through the saw the two shakes produced from each of the sawn boards are discharged from the board-gripping elements and the latter are then carried along a return path to their starting position for receiving another board to be resawn.

The carrier members which the work-gripping elements are moved and guided in elongated circuitous paths comprise, on opposite sides of the cutting plane, the endless chains to and i2 driven and guided by pairs of sprockets it and located at opposite ends of the machine so as to dispose the chain stretches horizontally between the sprockets. the chains it and B2 are spaced equal distances As shown in Figure 4, l

from. the vertical cutting'plane CP; The. chain.

by the feed-in. device F they are initially sup-- ported and conveyed on a longitudinal. edge bythe knurled live roll 22 and subsequently also. bythe live roll 24. The roll 24 is keyed to a counter shaft 26 driven by sprockets and a chain 28 interccnneoting the shafts 26 and 18. The knurled roll 22 rotates freely relative to the drive shaft. 58 supporting it and is driven from countershaft.

ml at substantially the same peripheral velocity as. the roll 25 by means of sprockets and a chain (Figure l). The shaftzt is also drivingly con-- heated by sprockets and a chain 32 to a'third shaft 34 spaced further along the feed path of boards and upon which the live roll 35 is rotatively supported in position of alignment of its upper surface with the aligned upper surfacesv of the two live rolls 22 and 24. The live roll 36, however, is driven at a slower speed than the rolls 22 and 2d and, in fact, at a slower speed peripherally than the speed of the carrier chains iii and [2, for a reason which will become apparent. The three rolls constitute merely impositive or frictional-drive conveyor elements which serve special purposes to be described in connection with other features later herein.

Adjacent and parallel to the respective carrier chains iii and it are mounted the circuitous guide tracks is and 48 (Fig. 4), each at substantially constant spacing from the associated chain. These are double tracks-that is, they have outer and inner guide rails 33a, 38b and 40a, 4612, respectively (Figs. 5 to 7) between and along which the grooved slide blocks are guided for circuitous movement driven by the chains I6 and l 2, blocks 52 along track 38, and blocks d4 along track 49. These slide blocks carry the work-holder elements to be described and the upper sides of the tracks on which they slide establish a substantially constant lineal feed path along the cutting plane. Without such tracks the work-holder elements would be positioned by the carrier chains is and I2, hence their paths would tend to vary or change while advancing the boards through the saw, producing non-uniform results in resawing the boards.

Only a portion of the machine frame supporting the various shafts and other functional parts is illustrated, inasmuch as the details thereof are largely of incidental or secondary importance. In Figure 5, for example, the upper or outer guide track rails 38a and 40a are supported in their upper stretches by means of the frame arms 52, whereas the upper stretches of the inner guide rails 38?) and 491) are carried by the longitudinally extending frame plates 54. These plates are supported by their outer edges in horizontal position by the vertically disposed longitudinal frame plates 58 serving as supports for the several rotative shafts. In their lower stretches, the inner track rails 381) are carried by the horizontal frame plate 58 interconnecting the vertical plates 56; as shown (Figure 5).

With more specific reference to the slide blocks guided by the tracks 33 and At, a series of slide blocks tic, comprising five in number in the example, are positioned at equal spacings around the. track 38 and, alternating with the blocks 42a,

7. a second series of the same number of slightly different slide blocks 42b are likewise positioned at intervals around the track 38. The guide track 40 also has a first series of slide blocks a of the same number and at approximately corresponding locations as the blocks 42a on track 38, and a second series of alternate slide blocks b approximately similar in number and locations to the slide blocks 42b on track 38. Each of the slide blocks is connected to the respectively adjacent drive chain ID or l2 by means of an individual draw link 46, the leading end of which is pivotally connected to the chain pin 48 and the lagging end of which is pivotally connected to the slide block projecting pin 50, as shown (Figure 4). The length of each draw link is suflicient to permit slight variations in the spacing between the block pin 50 and chain pin 48 during movement around the path of travel, especially as the block rounds the 180 degree arcuate curves at the ends of the chain stretches. The links necessarily pivot on these pins to accommodate this change of spacing accompanying movement of the slide blocks around these turns. Moreover, such pivoted draw links permit the chain to sag slightly between sprockets without compelling the blocks sliding of the straight sections of guide tracks 38 and 40 to carry the weight of the chains as dead load causing undue pressure and wear on the tracks.

In order to permit the slide blocks, closely guided between the track rails on the straight stretches, to round the turns at the ends of the machine without binding, the blocks are of special form in cross section as indicated at the left in Figure 2. Having slightly chamfered outer face corners 44' and a recess 44 in the inner face intermediate the ends thereof, the shape or formation is such that the rear point r nearest the outer rail is located forward (by any small distance 722) of the rear point q contacting the inner rail. Thus as the slide block enters the turn moving to the left on the upper stretch in Figure 2 the block drops or tilts down about point q as a pivot, and the point r swings away from the outer rail rather than against it. The block then literally tends to swing or fall freely into the turn instead of hanging up at its entrance. Theoretically this action would obtain if the dimension m were zero but freedom from binding is definitely assured only by having this dimension of appreciable value.

In general, there are two pairs, a leading and a lagging pair, of gripping elements which make up a carriage set for holding a board in cutting position while advancing it toward and through the saw S, and these elements are carried by individual slide blocks guided by either of tracks 38 or 40 as the case may be. The pairs of gripping elements of each carriage set are spaced apart in their line of advance by a distance which permits them to engage the board side faces adjacent the respective ends thereof. Each such pair of gripping elements comprises a lateral board gauge having board contacting abutments thereon at fixed spacing from the cutting plane CP, and a cooperating presser device by which the board is pressed laterally against such gauge to establish the boards cutting position. While the presser means of the leading and lagging pairs of gripping elements comprising a carriage are quite similar in form, the lateral board gauges thereof, while adhering to a common principle of construction, differ somewhat as to detail. Located on opposite sides of the cutting 8 plane, the lateral board gauges are adapted to bear against the diagonally opposite free edges of the split boards in a manner described hereinafter.

lhere are five similar board carriage sets of gripping elements in the example, corresponding to the groups of slide blocks carrying such elements. The spaces along the circuitous path of travel occupied by these carriage sets are designated CI, C2, C3, C4 and C5 in Figure 2. More specifically, the leading pair of gripping elements of one set comprises the lateral board gauge 60 and the cooperating presser means 62, while the lagging pair of gripping elements in the same set comprises the lateral board gauge 64 and the coacting presser means 66, the four elements in the order named being carried, respectively, by the slide blocks 44a, 42a, 42b and b (F18- ure 4).

The lateral board gauge 60, of suitable form to serve its intended purpose when secured upon the inner side of the slide block 44a, has three projecting horizontal abutment strips 60a comprising its inner or board-contacting face. These strips, of appreciable length extending generally along the feed path at close spacing to the cutting plane CP, are actually placed at a slight horizontal angle to the cutting plane so as to converge slightly therewith in the direction of feed, namely to the left in Figure 4. Except near their trailing edges, which are only slightly inclined, if at all, to the cutting plane, so that board edges pressed laterally thereagainst do not tend to slide forwardly, abutment strips 64a of lateral board gauge 64 converge rearwardly relative to the cutting plane at a much greater angle than abutments 60a. Thus the trailing or board contacting portions of abutment strips 64a lie closely adjacent the cutting plane whereas their leading edges do not. The vertical spacing between the three abutments 60a of gauge 60 is the same as that of the somewhat similar abutment strips 66a of the gauge 64, as shown in Figure 5.

With reference to the latter figure, it will be noted that the lowermost of the three abutments 64a (hence of 60a also) will be typically located approximately one and one-half to two inches above the lower edge of a board supported on the live rolls, whereas the uppermost of the three abutments in either case will be located approximately six to seven inches above such lower edge. The intermediate abutment in each case is located approximately midway between the other two. The thickness of the upper and lower two abutments transversely to the cutting plane is approximately 1 6 of an inch greater than that of the intermediate abutment element-that is, the former project approximately 1 3' of an inch nearer to the cutting plane than the intermediate abutment. The significance of this difference of spacing will be described subsequently with reference to Figures 6 and 7 herein. These abutment strips are preferably formed of a material such as Micarta or a like frictional material having good wearing qualities when put to the use disclosed.

The presser means (62 and 65) of the two pairs of board-gripping elements comprising a carriage set are substantially the same in construction and operate similarly. Referring to the presser means 66, for example, as shown in Figs. 4, 5 and 8, the upright rocker shaft 66b carried by the slide block 44b serves as a pivotal support for the horizontally actuated presser arms 660, there being an upper arm substantially opposite .9 the intermediate abutment element Ma, and a lower :arin located somewhat lower than the lowermost of the three abutmentsttQ-a. The upper arm carries on its swinging end two contact pads, comprising rubber rolls 650;, while the lower arm carries a single such roller. A crank arm Gee upon the upper end of the rocker shaft 852?) car i351 a cam follower upon its swinging end. This crank ari'n may be swung from a position generally transverse to the cutting plane G? into substantial parallel relationship therewith. The two presser arms 56:: are independently rotatively supported on the shaft by means of the cylindrical sleeves and, as shown in Figure 8, these sleeves are rovided with circumferential slots 55 therein. Stop pins 68g secured to the shaft 632) are received in these slots and cause the sleeves to rotate therewith only when the pins abut the slot ends. In the normal (retracted) position of the presser arms such engagement exists, being caused by positioning of crank arm generally ,parallelto the cutting plane. Subject to this action of the crank arm, the separate coil springs 6571 encircling the respective sleeves apply force to the presser arms urging them toward "the adjacent side of the board.

The initial position of the presser arms as the boards are first delivered to the machine into the space defined between the gripping elements of a carriage set is the retracted position thereof, so that the boards will be received reely between the opposing pairs of gripping elements. However, the retracted spacing between the respective gripping elements is sufficiently close to prevent the board tipping over very far to either side while it is being advanced, on edge, upon the live rolls 22 and 24 during the initial phase of its travel toward the saw. Before the board reaches the location of the saw S, the presser tea of the presser device 355 and the corresponding and similar arms 62a of the presser device 62 are released by deflection of their crank: arms order to permit the springs in these devices to apply force through the presser arms to the board hold the board firmly in cutting position against the lateral and respectively. This action occu's substantially simultaneously in the devices and Gil, so that both ends of the boards will be swung into correct position at the same time. It is ciiected by the elongated track cams ES and it secured along guide track rails 35a and Ma, respectively. Such cams have inclined steps or ntrol surf -ces thereon which p01 the cam follower pins tied 821i swing simultaneously away from the cutting ne slide block." carrying them approach the saw location.

As will be noted in Figure 4, the lateral gauge located on opposite side of the board from the late al gauge to engage the free of board. The pusher gauge 12 carried by the b ock sediately baind lateral gauge t l projects therefrom transversely in relation to the cutting plan and engages the end of a board to position such end adjacent the trailing end of the almtrnents boards end t -en lies against the Actuation of the associated presses the boards ec ges ch abutments and disposes the board n incline to the cutting plane as desired.

In order to insure that the board will be correctly positioned with its .raiiing end against the pusher-gauge T2 before the presser arms are actuated for spring operation and the board is clamped firmly in place between the gripping elements, a yieldable detaining stop it! (Figs. 2 and 4) is provided at a fixed location somewhat ahead of the saw. This detaining stop is projeoted into the path of a board being rapidly advanced on the live rolls 22 and so as to arrest movement or" the board for a short period of time. The board is thus held stationary against the continual impositive driving force of the friction rolls until the pusher gauge 72 of the slower moving carriage set comes up from behind and engages the boards trailing end. The board is then advanced positively a short distance, pushing down the yieldable stop 14, before the cam follower pinssiia' and 62d ride outwardly on the cam surfaces Tila and 98a, respectively, to effect gripping of the board in the holder elements.

In order to achieve this type of action, the detaining stop it comprises the retractible stop abutment element Ida which is carried on an arm Mb pivoted on a transverse horizontal shaft Me in order to swing such stop element intoand from the feed path of boards. A spring Md interconnecting the'end of the arm Mb and a fixed support Me on the machine frame is so located that its line of force crossesover the pivot axis during the process of swinging the stop element l lo between its projected position in Figure 2 and its retractedposition shown by dotted lines in the same figure. Thus the spring holds the stop yieldably in projected position, whereas it also holds the stop in retracted position until raised positively, as by counterclockwise swinging of the actuating arm 16a. This actuating arm comprises part of a bell crank 16 which is pivoted on a tnansverse horizontal shaft '19. A bell crank control arm it?) normally projects into the path of advance of an abutment element I8 carried by one of the leading slide blocks of the carriage set. When this abutment engages the upper end of the control arm, the latter is swung progressively counterclockwise by continuing ad- Vance of the carriage mechanism, and the swinging end'of the actuating arm 15a then raises the detaining stop l'll into projected position. This is timed to occur immediately before the leading end of the advancing board reaches the detaining stop. Because of the finite length of the abutment l8 engaging the end of the control arm 16b, there is a short but appreciable period during which the actuating arm 16a is pressing or hold ing the stop I4 positively in its projected position. This period of time is sufiiciently long that the board's momentum is absorbed by the stop before on the stop can force it back down and allow the board to escape past it at that time.

In orderto establish positional synchronization or timing between the positive holding period of the detaining stop and the instant of impact thereon of the board, a board-restraining stop as is carried by the traveling slide block 422) of the next preceding carriage set and projects transversely with relation to the cutting plane. This restraining stop is overtaken by a board on the rapidly driven live rolls 22 and t t, and retains the board so that it is traveling in definite position relative to the associated carriage set when it approaches and finall reachcs theloca tion of the detaining stop it. The remaining problem in timing is then simply a matter of locating the abutment IS on the associated slide block or runner so as to actuate the detaining stop M just prior to the instant of arrival of the board at the stop. With correct timing thus established, the period of holding the stop 14 positively in projected portion may be made very short, so that almost immediately after impact of the board thereon, the ensuing impact of the board's trailing end by the pusher gauge may be caused to occur and the boards advance continued without wasting time. Resumption of a boards movement effected by the pusher gauge 12 occurs sooner, of course, with a long board than with a shorter one.

The basic purpose of live roll 35, driven at a somewhat slower rate than the feed rate of the board-gripping elements, is to provide a support for a board being advanced by the rapidly driven rolls 22 and 24 which support does not greatly hinder or retard the initial rapid advance of follower pins 66d and 62d reaching the cam control surfaces 10a and 68a to secure the board firmly against any possible longitudinal shifting out of position before reaching the saw. Reversely inclined control cam surface 881) (Figure 1) is located beyond the saw to release the boards leading end from the leading gripping element pair 60 and 62, before they enter the downward turn in the track. Control surface 10b releases the board's trailing end from pressure of arms 66a just before the board is sawn throu h (dotted line position at left in Figure 4), in order to spare the saw from lateral pressure when the board halves are severed from each other. However, the arms 6611 are reoammed into holding position after sawing is completed and the board parts are beyond the saw in order to hold them on the saw table if and prevent their dropping down between the tracks as soon as their centers of gravity pass the end of the table. This allows picking up or removing the boards more conveniently from the machine than otherwise. Such recammine is affected by cam surface 100. A subsequently engaged cam surface 10d effects release of the boards from elements 64 and 66 before they enter the curve in the tracks at the dischar e end of the machine.

The several work-holding elements have suitable inclined guide surfaces which minimize the possibility of a board, especially a relatively short one, becoming caught thereon and failing to become seated properly therebetween in order to be gripped in cutting position when the time comes. For example, the lateral gauge 64 has the abutment strips 64a inclined at an appreciable angle to the cutting plane CP which tend to guide the trailing end of a board into engagement with the pusher gauge 12. A flat plate 64b extending forwardly and outwardly from the leading ends of the abutment strips 64a at a greater inclination to the lateral location of the guide track 38 affords supplementary guidance to the same end, as does the guide plate 661' on the opposing presser device (Figures 2 and 4), such plate having slots therein permitting the presser arms 66a to be retracted behind such 12 plate where they will not interfere with the action thereof in guiding the end of a board into contact with the pusher gauge 12 as the latter moves forward relative to the board. A guide face 60b inclined to the cutting plane is provided on the rear inner corner of the lateral gauge 60 in order to facilitate the insertion of boards into the space between it and the opposing guide plate 621' of the coacting presser device. Normally, however, the boards will be placed in the machine with their end portions located generally between the proper holding elements of a carriage set so that the chances of the board becoming caught out of proper position are small.

Adjacent the saw along the feed path is a supporting roll 82, the upper side of which is in line with the upper sides of the preceding rolls 36, 24 and 22. The roll 82 supports the lower edge of the board against downward pressure of the saw S as the board is actually being sawn. Preferably the surface of this roll is provided with a series of sharp circumferentially extending ribs or knife edges, formed as by grooving the roll circumferentially at close intervals along its length, so that when the saw pressure forces the board downward against the roll these sharp annular projections bite into the wood. The roll is suitably journalled against displacement under endwise thrust, and by biting into the wood prevents the lower edge of the board from sliding transversely to the cutting plane and causing it to tilt under saw pressure should there be a tendency to do so as a. result of the lower edge of the board being beveled or uneven and the line of contact between the board and the roll being offset from the cutting plane. The action is illustrated in connection with Figure 7. In that figure the board has a. beveled lower edge which actually contacts the supporting roll 82 at an appreciable lateral distance d from the cutting plane CP, hence the application of saw pressure to the board tends to tilt the board laterally in a counterclockwise sense about the point of contact on the roll 82. As a corollary the lower edge of the board tends to be slid to the right along the roll 82 causing outward yielding of the lower presser arms 62a and thereby causing a curved cut in the board. The serrations on the presser roll 82 bite into the wood and assist the lower presser arm to hold the lower portion of the board against the lower lateral abutment 60a so that saw pressure cannot displace the board as it is being out. In the illustration of Figure 6 the lower edge of the board is not entirely squared with relation to the sides but the line of contact thereof with the serrated roll 82 is substantially coincident with the cutting plane of the saw. Hence the saw pressure exerted downward in the cutting plane is stably resisted, as if the edge were squared, and there is little or no tendency for saw pressure to tilt or slew the board to one side or the other. The sharp projections on the roll 82 preventing lateral sliding of a board edge thereon are preferably formed as circumferential or angular knife edges; however it will be evident that continuous edges are not essential since a series of points or like forms will accomplish a similar result. The term annula.r" applied to these projections is intended to embrace the various equivalent forms thereof.

Figures 6 and 7 particularly illustrate certain aspects concerning the operation of the boardgripping elements. In Figure 6 the end portion of a narrow board Bn is being gripped between accuses '13 the lateral board gauge 69 and the :coactin'g presser device 62 comprising'the upper and lower presser arms etc. The board has been placed in the machine so that its free edge, i. e., its smoothest edge Bn faces against the lateral gauge 6t, leaving the comparatively rough opposite edge to be engaged by the rubber rollers 62a. In this the free Be is fairly smooth and the board is suiiiciently narrow that its upper edge rails to reach the upper of the three abutments tea, hence contacts only the intermediate abutment and the lower abutment. The upper and lower presser arms 66a, being independently mounted and spring-actuated, apply gripping force to the side of the board, pressing it firmly against these abutments despite any difference in board thickness at the locations of contact of the presser rolls 52a carried by the respective arms. Because the lower contacted abutment lies closer to the cutting plane than the intermediate contacted abutment, this narrow board will therefore be inclined slightly from the vertical so that the tip of the shake being cut in the saw will be slightly thinner near the lower longitudinal edge of the board than it will the upper longitudinal edge thereof. However, because the board is narrow this difference is slight and ordinarily will not be noticeable, especially in view of the roughness of the board on its opposite side.

In Figure "7 the boardBw comprises a relative- 13; wide board which is of a su ueient width vertically to more the span the distance between the supporting roll and the uppermost abutment element In case, however, the

board near free edge Ew' instead of being fairly smooth as in the ease of the board Bra in Figure (3, happens to have a hump or projection is whic contac s the in ermediate oi the abutments Because the intermediate abutment is spaced farther from the cutting plane than the lower abutment, however, the hump It does not cause til. .ng of the board greatly if at all from the ver cal, In other words, despite the considerable w.e cf the board tending to multiply in terms of tilt any irregularities of the thereof engaging the abutment-s 653a the boards upper edge is not displaced far from the desired. cutting position by the hump h, because of the setback. of the intermediate abutment is true of the action of abutments In effect, therefore, the gripg device deliberately tilts a narrow board sligh r on to the vertical cutting plane o a to minimize the much greater abl oiiset of the upper edge ntact the intermediate abutments. instead h a hump h the same board has a rec r ate its upper and lower .euiate abutment will not be cont? l the board will be supported substantially ver ally, pressed against only the upper low r abutments,

vi 1th to i, it will now be ape abutments should be inclined all angle to the cutting the direction of feed. This angle the desired horizontal angle be- 6 no the board inclined .uting position. Thus while the sh re boards actually very one or more hes in length, example, so that thepoints contact of their leading free edges with the abutments will vary along the length of "the J. edges 'albutments the tip thickness of the sawn shakes will not vary appreciably.

The reason for having the abutment-s 54a at a much greater'inclination angle with relation to vinents ii-Ga does not apply in the of the abutments "54a. This is true because the lagging froe edge of a board, being located by the pusher always contacts abutnients tea at substantially the same place, assuming, of course, the end of the board is substantially squared.

Operation With the clutch engaged, the live rolls 22 and 2d are rotated at a peripheral speed somewhat higher than the lineal speed of the carriage chains is and I2 and the live roll is rotated at a peripheral speed somewhat lower than such chain speed. The board carriage set of workgripping elements, designated C! in Figure 2, is shown moving counterclockwise around the turn at the input end of the machine and the presser devices 82 and 88 of such set are then held in retracted position by the control earns 63 and Ill. A board Bl (Figure 3) from the delivery device F may then be freely inserted on edge into the space between the separated gripping elements. Contact of the generally upright looards lower edge with the knurled live roll 22 drags the board along the feed path toward the saw and causes its leading end to overtake. and press against the traveling restraining stop 85] located just ahead of the carriage set C l The board 132 in the carriage set Ciaimmediately preceding the board Bl has been advanced farther. along'the feed path by operation of the live rolls and isibeing detained by contact of its leading end with the detaining stop M. In order to arrest board 132 being advanced on the live rolls as indicated, the detaining stop 74 had just'previously been actuated into its projected position by engagement between control arm 76?) and the traveling abutment it carried by a trailing slide block so of the next preceding carriage set C4. Timing of the actuation of the detaining stop into projected position so as to hold the stop positively in that position until the boards momentum is absorbed upon impact with such stop is assured by contact of the boards leading end up to that instant with the restraining stop '80 carried slightly behind the preceding carriage set C4.

In the indicated position of set C5 relative to the -sso'ciated board B2, the pusher gauge 12 of this carriage set is moving up behind the leopard B2 and about to contact its trailing end. When that happens the board will be pushed further towards the saw positive rashion, forcing down he detaining SE09 it. Continued movement of the carriage set C5 and board B2 toward the saw produces actuation of the presser devices of such carriage set by reaand-is or has been released by cam surface 10b from associated grippers 64 and is about to be released from grippers 6Q, 62, by cam surface 68b. The grippers G4 and 65 are subsequently actuated by cam surface lite for holding the board B3 on the table t after sawing, but are later again deactuated cam surface 75d to release the board finally for removal.

During the course of sawing the board B3 its lower edge is forced downward by saw pressure against the serrated supporting roll 82 which assists in holding the board against lateral slewing or shifting as a result of saw pressure when the board's lower edge does not contact the roll 82 directly in the cutting plane as previously described.

Upon completion of the sawing operation, the two split-resawn shakes produced from a board will emerge from the discharge end of the machine released from the associated gripping elements as have been the shakes sawn from the board Bl at the left in Figure 3. The gripping elements of the associated carriage set then return to the starting position along the lower path of the drive chains to receive another shake board for sawing.

The operation constitutes an endless feeding of shake boards in close succession through the saw S, as desired.

We claim as our invention:

1. In a shake board resawing machine, board positioning and feed mechanism operable to advance a shake board generally endvzise progressively toward and through the saw location with the board in cutting position disposed at an incline relative to the cutting plane in the direction of feed, said mechanism comprising a set of work-holding elements including opposed normally separated board-gripping members dis-- posed on opposite sides of the cutting plane and operable for gripping a shake board in cutting position therebetween, carrier means driven for moving said gripping members conjointly along a feed path parallel to the cutting plane toward and through the saws location for cutting the board held between said gripping members, a pusher gauge connected to and movable with said carrier means behind said gripping members for engaging and pushing the board positively along the feed path by the rear edge of such board held in cutting position between said gripping members, frictional drive conveyor means disposed and operable for advancing a board impositively in the direction of feed ahead of the pusher gauge, means for driving said conveyor means at a faster rate than said carrier means, yieldable detaining stop means stationarily positioned ahead of the saw in the path of feed to arrest a board being advanced impositively by said frictional drive conveyor means, whereby the board is overtaken by the pusher gauge for positive, further advancement thereof located between said gripping members causing yielding of said stop means, and gripping member actuating means including a first control element located effectively beyond the detaining stop and in advance of the saw location along the feed path operatively for actuating said gripping members to grip the board in cutting position therebetween following engagement of such board by said pusher gauge, said actuating means further including a second control element located beyond the saw location operable for deactuation of the gripping members to release the board after sawing thereof.

2. The shake board resawing machine defined in claim 1, and a traveling restraining stop connected to and movable with the carrier means preceding the gripping members and disposed in the path of feed of the board on the conveyor means, said restrainin stop thereby engaging the leading end of a board being impositively advanced by the conveyor means and limiting the outdistancing travel of the board relative to the pusher gauge prior to the boards arrest by the detaining stop means.

3. The shake board resawing machine defined in claim 2, and means releasably holding the detaining stop normally retracted out of the feed path, and stop-projecting means actuated by movement of the gripping members approaching the location of said detaining stop for projecting said detaining step into the feed path of the board.

4. The shake board resawing machine defined in claim 3, wherein the stop-projecting means comprises a traveling abutment movedly connected to the carrier means for advancing generally along the feed path with the gripping members, and the stop-projecting means includes a member actuatable to hold the stop in projected position. positively and a contact element engaged by said traveling abutment during such advancement for actuating said member, said traveling abutment and cooperative contact element having mutually contacting surfaces formed for prolonged engagement during such advancement for maintaining the detaining stop in projected position positively for a period sufficient to absorb the momentum of the advancing shake board impacting thereon.

The shake board resawing machine defined in claim 4, and a live friction roll driven slower than the carrier means and thereby maintaining the board against the pusher gauge engaging such board.

6. The shake board resawing machine defined in claim 3, wherein the set of work-holding elements comprises two pairs of board-gripping members spaced apart in the direction of feed for gripping a shake board by its broad side faces near opposite ends thereof, respectively, the members of one such pair comprising a lateral board gauge fixed in parallel relation to the cutting plane on one side thereof, and normally retracted presser means disposed in the opposite side of said cutting plane and actuatable for movement alternatively toward and from the lateral board gauge to press the shake board firmly therea-gainst, as with one froe edge of the board contacting said gauge, and to release the board from such pressure, and the members of the other pair of board-gripping iembcrs comprising a second lateral board gauge disposed in fixed parallel relation to the cutting plane on the opposite side thereof from the that lateral boa-rd gauge, and normally retracted presser means opposed to said second lateral board auge and actuatable for movement toward and from the same to press the shake board firmly thereagainst, as with the opposite froe edge of the board contacting said gauge, and to release the board from such pressure.

7. The shake board resawing machine defined in claim 6, wherein the respective presser means have actuating cam follower elements operatively connected thereto for moving the presser means toward and from the board sides, and the control elements for actuating the gripping members are comprised of track cams engaged by said cam follower elements, respectively, and extending generally parallel to the direction of feed on opposite sides of the cuttingplane, said track cams individually having first and second cam follower deflecting control surfaces thereon at respective locations along the feed path eflecting substantially simultaneous action of the two presser means following engagement of the board by the pusher gauge, and effecting substantially simultaneous retraction of the two presser means from the board after sawing thereof.

8. The shake board resawing machine defined in claim '7, and spring means interposed between the cam follower elements and the presser means associated therewith for transmitting actuating force to the latter and thereby establishing gripping pressure on boards of difierent thickness.

9. The shake board resawing machine defined in claim '7, wherein the individual presser means comprise a rocker shaft extending transversely to the line of feed movement, a plurality of presser arms, first pivot means on said shaft including separate elements supporting the respective arms for independent swinging on said shaft, second pivot means on said shaft pivotally supporting the associated cam follower element for swinging thereon, coupling means interengaging said first and second pivot means for effecting simultaneous retraction of said presser arms by movement of said cam follower element in one sense, and separate coupling spring means interposed between said second pivot means and the respective elements of the first pivot means for transmitting force to said arms swinging them against the board by reverse movement of said cam follower element, whereby pressure of the individual arms against the board is established independently of thickness variations or curvature and irregularities of the adjacent side of the board contacted by said arms.

10. The shake board resawing machine defined in claim 9, wherein the lateral board gauges individually comprise board-contacting abutment elements spaced apart widthwise of the board and spaced substantially equal distances from the cutting plane corresponding approximately to the desired tip thickness of the resawn shakes, and an intermediate abutment element located between said spaced-apart abutment elements and spaced at an appreciably greater distance than the latter from such cutting plane.

11. The shake board resawing machine defined in claim 6, wherein the lateral board gauges individually comprise board-contacting abutment elements spaced apart widthwise of the board and spaced substantially equal distances from the cutting plane corresponding approximately to the desired tip thickness of the resawn shakes, and an intermediate abutment element located between said spaced-apart abutment elements and spaced at an appreciably greater distance than the latter from such cutting plane.

12. The shake board resawing machine defined in claim 11, and a board guide roll extending transversely to the cutting plane adjacent the saw location to support the board against saw pressure during cutting, said guide roll having sharp annular peripheral projections thereon biting into the boards edge, preventing lateral skidding or slewing of a board with a beveled edge contacting said guide roll.

13. The shake' board resawing machine defined in claim 6, and a board guide roll extending transversely to the cutting plane adjacent the saw location to support the board against saw pressure during cutting, said guide roll having sharp annular peripheral projections thereon biting into the boards edge, preventing lateral skidding or slewing of a board with a beveled edge contacting said guide roll.

14. The shake board resawing machine defined in claim 1, wherein the conveyor means comprises a series of board-advancing live rolls positioned at intervals along the feed path to engage and advance a board along such path toward the saw, and a board-supporting guide roll located immediately ahead of the saw with its axis transverse to the cutting plane, said guide roll supporting the board against saw pressure during cutting and having sharp annular projections on the periphery thereof biting into the boards edge under such pressure, preventing lateral skidding or slewing of the board with a beveled edge contacting said guide roll.

15. In a shake board resawing machine, board positioning and feed mechanism operable to advance shake boards in successive order generally endwise along a feed path progressively toward and through the saw with the boards positioned for cutting at an incline relative to the cutting plane in the direction of feed, said mechanism comprising a pair of endless carrier chains, means moving said chains in circuitous paths including parallel feed path stretches extending along opposite sides of the cutting plane, circuitous guide tracks extending along each chain and defining a lineal board feed path therebetween coinciding with the cutting plane, an even numbered plurality of runner elements for each chain, guided on said tracks and connected to and movable with the respective chains in sets of two at intervals along the lengths thereof, the runner elements of each set being spaced apart from each other along said tracks by approximately the length of a shake board and those on one chain being located in corresponding opposite positioning to those on the other chain to form coacting carriage sets each for supporting and advancing a single board therebetween, lateral board gauges carried by every other runner element on each chain in alternate arrangement to lateral board gauges carried by every other runner element of the other chain, said lateral board gauges of each carriage set having contact surfaces adapted for engaging the respective opposite froe edges of boards to locate the same in fixed adjacent position relative to the cutting plane in the cutting position of such boards, normally retracted presser elements carried by the remaining runner elements of the respective chains and laterally actuatable for pressing the boards in cutting position against the contact surfaces of said lateral board gauges, elongated stationary track cams extending along the board feed path stretches, and cam follower means guided on said track cam and movingly connected to the presser elements for actuation and deactuation thereof, said cams having control discontinuity surfaces thereon located along the board feed path at respective positionings for actuating the presser elements of each carriage set automatically by approach thereof along the feed path to the saw location and for deactuating such presser elements by movement thereof beyond the saw location, respectively.

18. The shake board resawing machine defined in claim 15, and frictional-drive conveyor means extending along the lineal board feed path defined by the guide tracks in position to frictionally engage and advance a board along the feed path, means for driving said conveyor means at a faster rate than said chains, yieldable detaining stop means stationarily positioned along the feed path to engage and arrest a board being advanced by said conveyor means, and pusher gauges disposed in the board feed path and connected to and movable with one of the chains at locations therealong closely behind the rearmost or trailing board gauges of the respective carriage sets for advancing therewith and engaging the trailing end of a board being arrested by said detaining stop, thereby to continue the boards advance positively, causing yielding of said detaining stop.

17. In a shake board resawing machine, means to feed boards generally endwise in succession along the cutting plane and through the saw location, comprising an endless carrier member, means disposed on one side of the cutting plane for driving and guiding said carrier member around a circuitous path having one substantially straight feed stretch extending parallel to the cutting plane, a plurality of board holder element sets connected to and movable with said carrier member at spaced locations along the length thereof for feeding boards successively through the saw, one holder element of each set having a board contacting surface thereon facing toward and spaced from the cutting plane for locating one froe edge of a board at approximately the resawn shakes tip thickness from the cutting plane, and the other holder element of each set being laterally movable toward and from the board to press against the adjacent side thereof and release the same from such pressure, alternatively, board positioning means cooperating with said holder element sets for inclining the respective boards associated therewith relative to the cutting plane to be sawn on a bias, said positioning means comprising a laterally movable presser element disposed on the opposite side of the cutting plane from the first holder element of a set in process of advancing a board through the saw, means actuating said laterally movable presser element to press one froe edge of such board firmly against the contact face of such first holder element, and a laterally fixed locating gauge contacted by the opposite froe edge of such board, spaced from the cutting plane by approximately the resawn shakes tip thickness generally opposite the movable holder element of said moving set, and means actuating said movable holder element for pressing said board by its latter froe edge against said gauge accompanying such advance of the board through the saw.

18. The shake board resawing machine defined in claim 17, and board locating gauges movedly connected to the endless carrier member adjacent corresponding end elements of the respective holder element sets, said locating gauges projecting transversely to the cutting plane for engaging one end of the individual boards being advanced along the feed stretch toward the saw.

19. The shake board resawing machine defined in claim 17, and board conveyor means frictionally engaging and advancing the individual boards along the feed path toward the saw location impositively, means for driving said conveyor means at a faster rate than the movement of the endless carrier member, and restraining stops connected to and movable with the endless carrier member beyond the leading elements of the respective holder element sets, said restraining stops projecting transversely to the cutting plane for engaging the leading ends of the individual boards being advanced along 20 the feed path toward the saw and thereby preventing such boards from advancing past the respectively adjacent holder element sets on the approach to the saw.

20. The shake board resawing machine defined in claim 17, and board conveyor means frictionally engaging and advancing the individual boards along the feed path toward the saw location impositively, means for driving said con veyor means at a faster rate than the movement of the endless carrier member, and restraining stops connected to and movable with the endless carrier member beyond the leading elements of the respective holder element sets, said restraining stops projecting transversely to the cutting plane for engaging the leading ends of the individual boards being advanced along the feed path toward the saw and thereby preventing such boards from advancing past the respectively adjacent holder element sets on the approach to the sam, a yieldable detaining stop located adjacent the path of boards approaching the saw and projected into such path to detain a board against the impositive advancing force of said frictional conveyor means, and pusher gauges connected to and movable with the endless carrier member to project transversely to the cutting plane at locations along said carrier member adjacent the trailing end elements of the respective holder element sets and thereby engaging and positively advancing the boards by their trailing ends toward the saw overpowering said detaining stop.

21. The shake board resawing machine defined in claim 20, wherein the means actuating the presser element and the laterally movable holder element comprise cam means having guide surfaces extending generally parallel to the cutting plane along the feed path, cam follower means guided on said guide surfaces and operatively connected to such presser element and holder element for actuation and deactuation thereof toward and from the cooperative holder element and locating gauge, respectively, thereby to grip and release a board disposed therebetween, said cam means guide surfaces having a holder element actuating portion located therealong in advance of the saw location but eifectively beyond the detaining stops location, causing deflection of said cam follower means to eifect gripping of a board, and a holder element deactuating portion located therealong beyond the saw location. and causing reverse deflection of said cam follower means to effect release of the resawn board from the holder and cooperative positioning elements.

22. The shake board resawing machine defined in claim 17, wherein the cooperative positioning further comprises a second endless carrier member disposed on the opposite side of the cutting plane from the first carrier member, means driving and guiding said second carrier member conjointly with the first carrier member in a cir cuitous path, and a plurality of presser elements and locating gauges connected to and movable with said second carrier member in numbers and positions thereon corresponding to the respective holder elements of the first carrier member cooperating therewith for holding and positioning of boards being fed through the saw thereby.

23. In a shake board resawing machine, means to hold a board by an end portion thereof in fixed position relative to the cutting plane comprising a lateral supporting gauge disposed for engaging a board's froe edge or the like, said gauge having board-contacting abutments thereon spaced from each other parallel to the board's width by a distance less than the contacted width of the widest board but greater than he contacted width of the narrowest boards to be resawn in the machine, means supporting said gauge with said abutments spaced by equal distances, less than the thinnnest boards thickness, from the cutting plane, said gauge having a third board-contacting fixed abutment thereon located generally intermediately to the firstnamed abutments and spaced appreciably farther from the cutting plane than the first-named abutments, presser means disposed on the opposite side of the cutting plane for engaging the opposite side of a board positioned for cutting in contact with said abutments, and presser-actuating means operable to advance and retract said presser means to and from such board for gripping and releasing the same against said gauge.

24. The shake board resawing machine defined in claim 23, wherein the presser means comprise a first presser element disposed substantially opposite one of the first-named abutments, a second presser element disposed substantially opposite the intermediate abutment, means guiding said presser elements to permit movement of each thereof against the board independently of the other, and wherein the pressure-actuating means comprises a movable member and separate actuating springs interposed between such member and said pressure elements, respectively, to trans mit actuating force to the latter for application to the board despite nonuniformities of the boards face engaged by said presser elements.

25. The shake board resawing machine defined in claim 24, and guide means engaged by one edge of a board gripped in the holder means, means supporting said guide means for locating said boards edge adjacent one of the first'named abutments on the side thereof away from the other abutment.

26. The shake board resawing machine defined in claim 25, wherein the guide means comprises a roll located adjacent the saw and having sharp annular projections on the periphery thereof which bite into the boards edge under pressure caused by sawing and thereby prevents lateral skidding or slewing of a board having a beveled edge.

27. In a shake board resawing machine, leading and lagging board holding elements gripping the board near opposite ends thereof at an incline relative to the cutting plane, carrier means movingly connected to said holder elements for advancing the board through and beyond the saw, said leading and lagging board holding elements each having abutment means at fixed spacing from the cutting plane contacted by diagonally opposite edges of the board and retractible presser elements contacting the respectively opposite board edges actuatable to press the board against said abutment means, and presser element control means comprising an element operable to deactuate the lagging presser element immediately preceding completion of the resawing of the board, an element operable to reactuate such lagging presser element immediately following passage of the sawn board parts beyond the saw location and thereby support such parts for further advance, and an element operable again to deactuate said lagging presser element for releasing the resawn board parts to permit removal thereof from the machine.

28. In a shake board resawing machine, board positioning and feed mechanism operable to advance shake boards in successive order generally endwise along a feed path progressively toward and through the saw with the boards positioned for cutting at an incline relative to the cutting plane in the direction of feed, said mechanism comprising a pair of endless carrier chains, means moving said chains in circuitous paths including parallel feed path stretches extending along opposite sides of the cutting plane, circuitous guide tracks extending along each chain and defining a lineal board feed path therebetween coinciding with the cutting plane, an even numbered plurality of runner elements for each chain, guided on said tracks and connected to and movable with the respective chains in sets of two at intervals along the lengths thereof, the runner elements of each set being spaced apart from each other along said tracks by approximately the length of a shake board and those on one chain being located in corresponding opposite positioning to those on the other chain to form coacting carriage sets each for supporting and advancing a single board therebetween, lateral board gauges carried by every other runner element on each chain in alternate arrangement to lateral board gauges carried by every other runner element of the other chain, said lateral board gauges of each carriage set having contact surfaces adapted for engaging the respective opposite froe edges of boards to locate the same in fixed adjacent position relative to the cutting plane in the cutting position of such boards, normally retracted presser elements carried by the remaining runner elements of the respective chains and laterally actuatable for pressing the boards in cutting position against the contact surfaces of said lateral board gauges, stationary cam means arranged along the board feed path stretches, and cam follower means engageable with said cam means and movingly connected to the presser elements for actuation and deactuation thereof, said cam means having control discontinuity surfaces thereon located along the board feed path at respective positionings for actuating the presser elements of each carriage set automatically by approach thereof along the feed path to the saw location and for deactuating such presser elements by movement thereof beyond the saw location, respectively.

ALVIN F. GLEDHILL. LEON R. LEWIS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 260,375 Estabrook July 4, 1882 288,173 Gowan Nov. 6, 1883 1,673,084 Loken June 12, 1928 1,796,369 Hirst Mar. 17, 1931 1,895,016 Whiting Jan. 24, 1933 1,934,087 Payzant et a1. Nov. 7, 1933

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