US2651336A - Chain saw - Google Patents

Description

Sept 8, 1953 H. E. WARREN 2,651,336

CHAIN sAw Filed July 11, 1947 3 Sheets-Sheet 2 BOO INVENTOR .x yHf/v/QY c". WAR/PEN,

Sept 8, 1953 H. E. WARREN 2,651,336

CHAIN sAw Filed July 11, 1947 s sheets-sheet' s MSA/RY VVA RR w @MNM/mwah ATTORNEYS s Patented Sept. 8, 1953 Henry E. Warren,

Ashland, Mass., assignor to Lombard Governor Corporation,

Ashland,

Mass., a corporation of Massachusetts Application July 11, 1947, Serial No. 760,237 3 Claims. (Cl. 143-135) 'Ihe present invention relates to power operated sawing machines of the chain type and to chain saws therefor. It aims to increase the cutting e'iciency of chain saws through an improved correlation of successive cutting elements, and to reduce manufacturing and maintenance costs as a result-of `new and improved constructions and arrangements of the link components. l In the drawings illustrating by way of example certain embodiments of the invention:

Fig. 1 shows a length of a chain saw in active position sawing crosswise of a tree, log or timber of which a portion is seen in cross-section;v

Figs. 2 and 3 are respectively front end and side elevations of one cutter link of the chain;

Figs. 4 and 5 arecorresponding views of another cutter link; Y

Fig. 6 is a sectiona1 view on a larger scale taken transversely of the saw and kerf, substantially Yas though looking from the left at Fig. 1;

y Fig. 7 is av view similar to Fig. 1 illustrating another construction for the saw chain o fthe invention;

Fig. 8 is a bottom plan view of the chain length Vof Fig, 7 l

Fig. 9 is a cross-sectional view of the chain as viewed from the left looking onto Fig.- '7; j

Figs. 10 andll are front andside elevations of Vone of the cutter links of the Fig. v'7 chain embodiment;

. Fig. 12 shows a connector link carrying a depthgauging guard and raker element; Figs. `13 and 14l are respectively a plan and a "side elevation showing a grinder means incorporated with the chain sawand comprised in the presentinvention, said views further illustrating the correlation of the cutter chain elements and the grinding instrument; and

Fig. 15 shows on a larger scale the chain links acted upon by the grinder in Figs. 13 and 14 but horizontally extended as in operative cutting position.

In the chain saw art as heretofore practiced it has been customary to employ various different shapes and types of teeth and cutting elements acting in generalto remove wood particles at the edges of the kerf so as to dene the 'latter and then to rout or rake out interior sections of the kerf. IIhe action of these cutting teeth has commonly been to ktear away particles of wood in a somewhat irregular manner requir- `ing a disproportionate power consumption Vas compared for example with the action of an ellicient cross-cut saw. The present invention is Vgenerally characterized by the provision of a separately imade or Vdesired: any convenient Vformk .of Vrakei' Vsingle functional type of cutting tooth acting in the `manner of a plane, chisel or plow and where- 1n` the extent of cut by successive cutting memrocal guarding action.

Referring lirst tothe embodiment of Figs. 1 to 6, in Fig. 1 a portion of the longitudinal guide plate of the sawing machine is indicated at I5,

are disposed in longitudinal alinement and are pivotally joined into a continuous chain by lateral pairs of connector links 50. Each pair of one at each side of the cenrespective end portions pivotally connected to the central links yas by riveting at 5 I, 52.

The central links prises a Ibody, a lower rear leg 22, 32, or 42 and in the illustratedrexample an upper body portion or lug 23,` 33, or-43 for guided travel along the guide plate I5. 'Ifhese blanks for the central link seriesare made of a strong and tough material such as spring tempered steel but which may be a relatively inexpensive stock as comparedwith that for the cutting elements or teeth proper in accordance with the present invention. These latter preferably are Yconstituted as tool bits formed of a v as high speed tool steel, tungsten carbide steel, Stelliteand others. These bits, one of which is seen in Figs. 2 and 3 and .another in Figs. 4 and 5, Vare-mounted 'inslots or recesses appropriately located on the-link blanks and lare held in-positionasv bysilver solder, copper welding VOrother suitableattachment A v, In 'accordance with the invention the teeth or cut ngj elements of the active links, whether provided at the spaces'to assist in clearing the heat resistant material such kerf. As slhown the rear legs 43 of the intermediate central links 40 are themselves constituted Aas such raker or clearer means 44.

In the embodiment of Figs. l to 6 the successive cutting teeth operate at different vertical levels. The central links 20, see particularly Figs. 2 and 3, carry the teeth, chisel bits or cutters 'which operate at a lower depth, These are centrally disposed with respect to the kerf and are comparatively narrow so as to form a lowermost center slot as indicated at 26 in Fig. 6.'

On certain others of the central links, namely the links 3-0, see Figs. 4 and 5 the chisel bits 35 operate at a relatively-higher level. TheseV cutters 35 are relatively wider'than the lower cutters 25 and also are symmetrically arranged` with respect to the center line of the kerf. Thus they balance forces against their opposite side edges. the total width of the kerf 35 and to form the bottom wall thereoffas at the level indicated-by the .numeral 31 in Fig. 6. The bottom wall of the center slot 26 at the level defined bythe lower chisel cuttertooth 25 is designated 21 in Fig. 6.

Further in accordance `with the invention the cutting depth foreach ofthe verticallyspaced chisel teeth or cutters 25 Aand 35 is determined by a guard preferablycarried by the same link and which rides on a surface formed by the cutter of the 4other level. As seen in Figs.-l, 2, 3 and 6, the links 2l)v have-at a level above the chisel tooth 25 anon-cutting guard 28 comprising a fiat plate .which` may be mountedl on the link 20 in a similar'manner as the sharp edged cutters 35 on the links 3D and at a level corresponding tothe latter. Theseguards 28 having a width not greater and preferably slightly less than the kerf 36 are adapted to ride on the bottom- 31 of` the latter. They limit the depth of the center slot 2B cut by the tooth -25 upon the same link 2U.

In a reciprocal and correlated fashion excessive penetration by the higher-level teeth 35 of the links is guarded against by an underlying non-cutting guard 38 shown as a portion` of the rear leg 32-of the particular link 30. This guard portion 38 by riding on the bottom 21 of the center slot 25 limits the depth of the bottom wall31'of the lkerf 35.

Thus the vertically spaced teeth or `cutters25 and ofthe links 20 and 30 are reciprocally guarded so that neither can penetrate more than a limited-distance beyond the other.' In this manner the work of cutting and forming the kerf is divided between the two levels of teeth and neither one is freeto dig into thewood beyond the calculated extent. This depth of penetration is determined by theheight relationship between each tooth 25 or 35 and its own guard 28 or 38 respectively, as measured with respect to the other positioned tooth and its guard. The resultant chain as herein disclosed has in practice afforded a highly effective cutting action, requiring less power than the conventional form. Some of the central links, herein the links 48, shown by way of'example asV alternating between the ` cutter links 28 and 30, have no cutters but being formed of similar blanks as the others-do 'have rear pendent legs 42. These may serve as clearers or rakers and may aord a supplemental guarding action in which connection they may also be supplied with guards or gauges similar tothe members 28 of the cutter links 20 if so desired.

The upper-level cutters 35 act to dene" Turning now to the further embodiment of.

series of links comprises right-hand cutter links 288, left-handcutter links 300 and intermediate non-cutting or clearer links 408, with pendent legs 220, 320 and 420 respectively. As in the previous example these may all have a common size and shape of blank one of which is seen separately in Figfllvf The central-links 200,` 300, 400 as before are`pivotallyinterconnected by pairs of -connector 'links 500i-and 5LB-some of which in this Ainstance additionally affordthe guarding and guiding function -to be-described.

In this Fig. 'l embodiment the'mutually cooperative cutter elements or teeth? proper have the form of -small plows, respectively disposed on the several linksin a-siderelationship instead of vthe vertical relationship-of thepreced. ing example. While they may be -formeddntegrally with the respective 'carrier links, preferably theyare fashioned separately as tool bits, of a special high-grade steel as previously mentioned, inserted and secured on'the rearlegs of the blanks as already explained;

Figs. l0 and ll show separately one of the cutter-links, namely-a right-hand link20ll.`Y For the purposes of description the terms right and left are applied to the-chain' saw andl the kerf las viewed 'from a position toward which the active run of the chain is travelling In Fig.` '1 the travel obviously is from right to left; and thepositional designations are applied as if looking endwise onto Fig. 'I from the left portion of the sheet.` Thus in Fig.A 10 the plow or 'cutter tooth 250 is projected to the-right of the link 200. In Fig. ll which is a right side elevational view` of a cutter link20ll ithe tool bit or plow tooth 250 will be understood as laterally projective Yout from the sheet and toward the viewer. The same applies also 'tothe cutter rlink 208 seen atthe'left portion of'Fig; 7, the latter to be compared also with the bottom plan of Fig. 8 and the cross-sectional and end elevational view of Fig. 9.

It 'will' be noted'that the sharpened lower cut'- ting edge of 'the'plowor'tooth' 258'has a slight inclination in two'directions; that is, upwardly 'fromright to vleft'as'seeninFigs'Q and V`10`.and alsoforwardlyirom the 'center' line of the kerf toward the side at which the tooth projects, noting particularly'ig; 8 in the latter connection. 'The plow 'teeth or cutters '350 for th'e'left-'hand links 380er@ simi'l'arlybutoppositely constructed and' arranged, laterally'ofthe' saw chain, as cleary seen" at the .lower `right central portion of Fig.

ByV reason of the plow-shape of the teeth' 250 and 358 the ribbon-like chips are turned away .from the'respective" teeth toward and-.into the `space at'the other side of the vkerf where they ,are taken up and carriedvalong For this purpose intermediate central links 4D8as inthe previous 'instance have'the rear legs 420"of vtheir blanks constituted as blunt or non-cutting clearers or rakers 440.

vIn Vthis Fig, 7 embodiment the horizontally offset cutterteeth 250 and 350 of the cutting links 200 and 300 are reciprocally guarded as to depth of penetration, by rightand left-hand means which also aid as rakers or clearers. Such means may be formed on the central links but preferablyr and as here shown is carried by certain of the connector links 510, one of which is seen separately in Fig. 12. The means Vreferred to comprises generally rectangular feet II and 5I2 pendent from the selected side connecting links 5IIl and having straight elongated bottom edges 5I3, 5M. As illustrated these depth guards are provided on one connector link 5H] of alternate pairs, and alternately at the left and at the right. The other connective link pairs 500 may besimilarly equipped or left plain as shown. I

These rakers and depth gauges 5I I and 5I2 are adapted tov ride on the uncut lateral portion of the kerf on the side opposite to the particular cutting tooth 250 or 35D which they guard, herein that next following. Thus, starting at the left in Fig. 7, a left-hand raker-guard 5II guides on the track just previously made by a left-hand tooth 35B (passed beyond Fig. '7) and thereby limits the depth of cut-to be made by the following right-hand tooth 2'50. In similar reciprocal fashion the left-hand cutting teeth 35, noting the central portion of Fig. 7, have the cutting depth gauged by the precedent right-hand guard 5I2 travelling on the right-hand track just cut by the right-hand tooth 250 immediately ahead of it.

The eiectiveness of the depth guarding action will be apparent from the following consideration. No single cutter or tooth 250 or 350 can dig below the active cutting level as shown in Fig. 7 unless permitted tortilt in a counterclockwise direction about the rear rivet or pivotal connective point 25| or 35I of the respective carrier link 200 or 30|). Such tilting mustinvolve a down movement of the leading portion of the same carrier link 230 or 30G, in the region of the fore pivotal connective point 252 or 352. Such down movement in turn is prevented by the contact of the guard surface 5I3 or 5I4 of the corresponding guard 5II or 5I2 upon the uncut wood at the opposite half of the kerf to that of the particular guarded tooth 2'50 or 350. In other words, the left-hand guards 5I I coacting with the left portion of the kerf are directly and -positively associated with the fore portions of the carrier links 26D having the right-hand cutting teeth 25) and limit the cut depth thereof. Similarly,lthe right-hand guards 5I2 engaging downwardly upon the right portion of the kerf are effectively carried at the fore portion of the carrier links 300 having the left-hand teeth 350 and accordingly control the cut depth of the latter. Thus in the Fig. 7 embodiment a reciprocal and correlated guarding action is had for the horizontally differentiated teeth 250 and 350 in a substantially similar manner as for the vertically spaced cutting teeth 25 and 35 of the previous embodiment. In both instances the cutters of one positional type are depth-guarded by a guard directly associated with the same link as the particular cutter but which rides upon the horizontal surface of the kerf formed by a cutter of the other or another positional type, thereby aiording a reciprocal correlation for the cutting depth as between the dilferent positional types of cutters. It will be observed with reference to both illustrative embodiments thatin'fthe saw. chain of the invention the work of cuttingthev kerfis divided between .two seriesof teeth,-.the=y two series being in vertical. relationship .in fonei instance and having a horizontal relationship in the other example. Each series of teeth is recipi-f. rocally guarded so that those of neither series cani penetrate more than a limited distancelbeyond those ofV the other series. At the same time sub-# stantially completeV lateral balance is accorded, with a minimum tendencyv of objectionable drag' or deviation at the sides ofthe kerf, the cutting-` elements being in each case symmetrically arranged with respect tothe center line of the kerf.'y By reason of this lateral symmetry there is balancing of forces against the opposite side portions ofthe chain.

A further important aspect of the inventionconjoint raker-guard elements are adapted `to receive automatic grinding while the sawfis. in operation in the normal manner, such grindingv herein being effected forv example atrtheflocae: tion where the chain bends around the arcuate! guide means or idler pulley at the outer ends of the supporting frame or blade of the chain-saw. In Figs. 13 to 15 a grinder means and the `manner vof cooperation with the saw chain rare' illustrated in connection Iwith the horizontally spaced tooth construction such as that of Figs.y 7to .12.

Referring now more particularly to Figs 13 and 14, the arcuate guide means for Athe chain shown by way of example as an idler pulley. isl indicated at 60, it being understood asl running upon a'pulley shaft 5I carried on the saw v'frame I5. The frame is longitudinally extended integrally or by means of a bracket 62.receiving support from the pulley shaft and adapted to mount a rotary abrasive element, disc or grinder 1U. As illustrated the grinder 'I0 has its shaft 'II eccentricallyjournalled in a circular bearer 12 rotatably supported on the bracket 62. Means is provided for rotatively adjusting the bearer l2, the latter as shown being formed with .cir-v cumferential teethv as at 13 engaged by a Wormvv 'I4 rotatable by knob 15. By

toregulate.. the depth of grind.l 'I'he grinder 10 may be driven through a exible shaft 16 driven from the saw power plant, motor or any convenient driven part of the saw assembly. The drive shaft 16 desirably has a detachable coupling 'with the grinder shaft 'II as at 11. If desired an auxiliary pulleyV 18 may be providedfor independent operation of the grinder. ff

In Fig. 14, looking at the opposite sideofthe saw to Athat viewed in Fig. 7, the-idler pulley 60 turns counterclockwise, and the lower runvof the chain moves from left to right toward active cutting position with reference to the work. A lefthand cutter link 300 (using the same hand designation as for Fig. 7) is at the grinding location.

at the region where 1n passing around link 300 has the relief angle thereof presented in correct grinding relation to the grinder 10, such that the latter tends to generate a circle of appropriate radius at the tooth surface. It

also. will be observed :that the guard surface 5M' Vbyp-the grinder 10. During operation the latter is. axially nxed and the location and path of grinding action is as described whether the grinder 10 is itself driven at the desired speed as throughthe means illustrated by way of example in Fig. 13, or is left at rest while the chain saw runs. `past it in grinding relation.

It is, apparent from thedescription in connectionwith the drawings that this commony and uniform grindingy action with respect'both .to the cutter teeth and to the corresponding guard surfacesis had by reason of their mutual construction and arrangement substantially as shown anddescribed, and particularly the relation. of theV pivot points 35| and 352 with respect to the said surfaces to be ground and to the bearing surfaces 501m and 5la of the connector links 500 v.and 510. These .latter engage the track osthe frame I5 and of the pulley E9 and accordingly determine the radial distance of the tooth and .guard surfaces concerned from the pulleyv axissBI.

In Fig. 15 a typical cutter tooth 356 and guard SI2 therefor as considered in Figs. 13 and 14 are shown on alarger scale in the working position, as when extended rectilineally between the idler or. arcuate guide 60 and the driving sprocket at the remote end of the frame I5. As thus generally horizontally travelling along the kerf in cutting wood,the guard 512 and the tooth 350 of the cutter link 300 respectively have the rear- Ward relief, and the difference in height indicated bythe broken lines in Fig. 15, appropriate for the mutual depth-g-uarding and cutting functions. The depth or height difference indicated represents the depth of freshcutto be made in the course of passage of the particular cutter along thekerf. As explained in connection with Figs. 7 to 12, each guard 5| I, 512 rides upon the i wood at the opposite half of the kerf from that of the corresponding cutter 250, 350, thereby correlatingthe cuttingaction of the horizontally .spaced series of cutters.

Itis important to note here that as the cutter teeth gradually wear down in use the provisions for automatic `grinding asillustrated and described in connection with Figs. 13 to 15 are such that the same mutual depth relationship is maintained as between the cutters and the corresponding guards. The grinder 10 may be adjusted from time to time by manipulation of the knob 15 to accommodate it to the extent of wear of the chain parts in actual operation. So far as I am aware the present invention for'the firsttime adapts a chain for accurate grinding while running in anormal manner and makes provision for accomplishing that result.

It will be understood that while in the foregoing description `with respect to Figs. 14 and 415 a left-hand cutter and tooth 30D, 350 has been referred together with the corresponding guard 5I2 the same grinding relation prevails also as to the cutter series 250 of opposite handsfand to the guards 5H therefor.

My invention either as to means or method is not limited Ato the exemplary embodiments or steps herein illustrated or. described, and I setforth its scope in my following claims:

I claim:

1. In a chain saw, an endless series of central links having pendent legs, connector links pivotally connecting the central links, the legs of some of the central links carrying single chisellike bits providing cutter teeth formed -to cut with a paring action along a substantially Yhori- Zontal surface, the legs of the other central links each constituted as a raker, said toothed links alternating with said raker links in the central series, the cutter teeth of alternate toothed links being positionally diflerentiated in the vertical and in the horizontal direction transverse of the kerf so as to out diierent bottom portions thereof, and a depth guard for each cutter-toothed link, such guard for the given tooth being directly associated therewith and being shaped, dimensioned and arranged as to both the vertical and horizontal directions so that such guard rides solely on that horizontal surface formed in the kerf by the precedent positionally differentiated cutter tooth.

2. A chain saw according to claim 1 in which the positionally differing cutter teeth are mutually onset vertically of the kerf and alternately are relatively wide and relatively narrow.

3. A chain saw according to claim 2 in which the depth guards for running on surfaces formed by the lower cutter teeth are carried on the same links with the higher cutter teeth, and vice versa, in the reciprocal and mutually coactive relation.

HENRY E. WARREN.

References Cited in the le of this patent UNITED STATES PATENTS

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