US269728A - simonds - Google Patents

Description

(No Model.)

l 4 Sheets--Sheet 1.

G. F. SIMONDS.

(moss GUT SAW.

Patented Deo. 26,1?827.

N. PETERS. Phulo-lllhngmphnr. Washmgon. D. C.

(No Model.)

G. F. SIMONDS.

4 Sheets-Sheet 2.

4 Sheets--Sheet 3.

(No Model.)

G. P. SIMONDS.

(moss GUT SAW.

/f/,Patented 1390.26, 1882.

faja/1, of j Jl( w CCQJ; (234% 7 fw@ /4 62mm 4 Sheets-Sheet 4.

l(No Model.)

G. F. SIMONDS.

GROSS GUT SAW No. 269,728. Patented Dec.26, 1882.

@yer/i073' NTTED STATES PATENT 'OEETCE cRosscuT-SAW.

SPECIFICATION forming part of Letters Patent No. 269,728, dated December 26, 1882.

Application filed October 27, 1882. (No model.)

.tion of a thisthack crosscut-saw that sha-lient a i1 even kerf throughout its length, that shall not bind in the cut, and that shall be relatively thickened and strengthened toward the ends, whereby more lumber can be cut and with less labor than as heretofore.

lily invention consists in a crosscutsaw of substantially uniform thickness throughout the length of its curved cutting-edge, and of grailually-diminishing thickness in the direction of its width from cuttingedge to back.

What is known as a crosscutsaw is usually a long thin plate ot' steel gradually narrowing in width from its middle toward each end, and

-having the edge in which the cutting-teeth are formed curvilinear in general contour; AAs such saws are intended for use in cuttinglogs and heavy timbers, provision needs to be made lor preventing theirbinding by reason of the closure ofthe walls of the kerf upon them, especially when the cut has been nearly completed and there is not left enough uncut material to keep the timber from sagging at that place. To compensate for such tendency to be bound in the kerfis the principal object of grinding the saw-plate, by which it is made to taper in thickness from the cuttingedge to .the opposite edge or"back, so called, and is thus enabled to be run without binding unless fthe sagging ofthe timber proceeds so far asto incline the walls ofthe kert' to each other at Van angle greater than that of the taper given to the saw-plate itself. The mechanical means commonly/employed for performing this grind-A ing has been primarily an ordinary grind- `stone and a presser-bar set across its acting face at an inclination corresponding to the de- 1n other words,

plane at right angles tothe direction ofthe ,".tween lthe grindstone and the presser-bar the saw-plate is passed, with opposite sides prelmotion of the grinding-surface at that place.

Through the angular space thus formed bel sented alternately to the grinding-surface at each successive passage, and the` back edge always toward the converging lines of the angie. In this way the portions of thesaw-plate adjacent to the back are first operated upon, and as they become reduced in thickness the back ofthe saw is made to enter farther in between the presser-bar and the grinder, until the whole plate is brought toa taperin the direction of its width.

The method of grinding crosscnt-saws heretofore practiced has been to move them in a rectilinear path. from end to end straight across the line of maximum action of the grinder. or substantially perpendicular to the plane which is common to that line and the presser-bar. By this means each plate was ground tapering in thickness transversely from cutting-edge to back at right angles to the straight path of its movement upon the grinder; but while suoli mode ot' treatment made the saw-plate better able to escape binding by the inclination of the walls of the kerf it produced defects which created other serious difliculties in the way ot' practical use, for itwill be perceived that as the saw was moved bodily endwise in a rectilinear path through the angular space between the in clined presser-bar and the surface ofthe grindstone the lines of uniform thickness in the tapered plate would rnn straight from end to end, and thus the cutting-edge of the sawplate, by reason ofits curvature and the consequent passage of its various portions through spaces of different widths between the presserbar and the grinder, was made to vary in thickness proportionately t0 its departure from a straight line; or, in other words, such curvilinearcutting-edge graduallyincreased in thickness from each end to the middle, and this inequality remained even after setting the teeth of the saw, because it was not feasible to increase the degree ot' their inclination tothe plane of the saw-plate by as much as they decreased in thickness, nor conversely. Hence every such crosscut.- saw would cut a wider -kerf along its middle than toward either end, and as a practical consequence whenever it was worked with a long stroke one of two undesirable results would follow-namely, either the teeth of the middle portion would bind in the kert' already made by the teeth of the portions located nearer the ends or would not run IOO at all in the narrower kert, but would ride over it and be occupied in performing the useless labor ot' enlarging the same by cutting down its walls. Furthermore, the comparative thinness ofthe saw-plate at and near its ends rendered it liable to kink or snap there in the at temp's of the workman to force it by pushing.

Before proceeding to describe my improved method of' grinding and the new productresulting therefrom, it will aid to a better understanding of the subject to further consider the cotiditions under which the old method ofgrinding has taken place, and some ot which are still present in the practice ofthe tiew method.

Thus far the positions and movements ofthe saw have been referred to the presser-bar and grinder; and it is evideiittliatin practice some tiiechanical means mtist be employed for perfoi ming the ottices of the presser-bar in holding the saw against the grinder at the proper inclination. Forexample.crosscut-saws have been ground between two grindstones actitig simultaneously on opposite sides ot' the plate, and in such case the grinding-surfaces, where they come into action, are inclined to each other at an angle corresponding to that ofthe taper to be given to the saw transversely, and they reciprocally,perform cach for the other the lunctions ot' a presser-bar; but for the purposes of' deiining the relationship of the sawplate to the. grinding-surface the presser-bar or its equivalent may be left out ot' account.

It will be readily understood that whether the grinding ot' the saw proceeds alternately on opposite sides, as with one griiidstoiie, or simultaneously, as with two grindstones, the transversely-tapering plate is substantially bisymmetiical with reference toa geometrical plane passing through the median lines of its edges. or, in other words, that such a platte divides it edgewise into two plate-s substatitially equal and similar each to each. .For convenietice of description we shall refer to this geometrical plane which symmetrically divides the plateedgewiseas the plane ofthe saw-plate. Further economy ot' description may be gained by denoting the line ot' maximum action ot'the grinder as simply the grinding-line, which, in the case ot' a machine employing a prt=sserbar, as already explained, would be located at the intersection with the grinding surface of a plane perpendicular thereto, and at right angles to the direction of motion thereof, passing through the presserbar longitudinally and centrally-that is to say, through what, for brevity, may be termed the axisof thepresser-bar; atid in the case of two grinders co-operating upon opposite sides ot' the saw-plate the grinding-line of each would he located at the intersection ot' the same plane with their respective grinding-surfaces, perpendicular thereto and at right anples to the direction of motion thereof. It slionld be understood, also, that the tertn grinding-line as here used is intended to signify not merely so much of it as is co-extensive with the actual dimension ofthe grinding-surface along the line oti its maximum action, but also the further geometrical extension thereof in the saine direction indefinitely. [n case of a griudstone the cylindrical periphery ot' which acts upon the saw-plate tangenti-ally, the grinding-line is parallel to the axis of the stone, and thc plane perpendicular to the grinding-surface. and at right angles to the direction of motion thereof', whose intersection therewith is coincident with the grinding-line, also passes through the axis 0f the griiidstone. It may liappeti that the periphery ot' the grinder is slightly convex, so as to grind the transverse taper of' the sawplate a little concave, in which case the actual grinding-line would be somewhat curved; but t'or the pui-poses of definition this variation is immaterial, since, whether theangnlar space between the grindstone and the presser-bar or its equivalent be bounded by converging curves or converging stra-ight lines, the sawplate, when in proper position therein for grinding, will always have its platte inclined to the grinding-line and its back toward the apex ofthe angle ot' inclination.

Instead of moving the saw-plate to the action ot' the grindstone in a rectilinear pat-h, I give it such movement as to cause every part ot its curved cutting-edge, throughout the entire length thereof, to pass successively through the plane which is common to the axis of the presser -bar and the grinding line at substantially the same point during any given passage, so that the lines ot' uniform thickness in the tapered plate are curves running substatitiallv parallel to the general curvature ot' the cutting-edge, because by 'keeping the cutting-edge ot' the saw-plate where it passes the grinding-line at the saine distance from the apex ot the angle of inclination of the presser bar all other portions which pass through any given cotistant part of the angular space between the presser-bar and the grinder, and which are consequently reduced to unit'orm thickness, will necessarily be acted upon at the same distance from the point at which the cutting-edge is maintained, and will therefore be located in a curve which conforms to the curvature ot' the cutting-edge. In accomplishing this movement ot the saw-plate, it will be made to describe a curvilinear path varying in form according to the direction taken by its ends while its cutting-edge passes the grinding-line at a consta-nt point. Thus, for example, it may be given a movement which is the resultant of simultaneous lateral atid longitudinal movements similar in character to that ot' which one member ofa parallel ruler is capable, the outetedge corresponding to the back ot' the saw-plate, and in such instance its successive positions will be parallel to one another, while as a whole it will describe a path the curvature of which is the reverse ot' that ot its cutting-edge; but l prefer, as a more convenient way ot' grinding my improved saw, to move the entire saw-plate in a curvilinear path substantially parallel to the general curv- IOO IOS

etarras.

ature of its cutting-edge; and to this end Il although it is obvious that the requisite moven'ients ofthe saw-plate between the grinder and the presser-bar might be giveir by hand,

especially with the aid ofa gage or stop against which to keep the cutting-edge ofthe saw-plate to insure its passage across the grinding-line at a tixed point. l am thus enabled not only to give uniform thickness to the cutting-edge ofthe saw throughout its entire length, but also to make the plate of the utmost strength and stiffness at the ends consistent with their narrower width. To be sure, the direction of the taper in thickness of the saw-plate from cutting-edge to back will vary somewhat, according to the specitic way in which my method of grinding is practiced-that is to say, when the parallelism ot" the successive positions of the saw-plate is maintained, as in the tirst exainplegiven, the taper in thickness will be in directions at right angles to the chord joining the ends of the curve ofthe cutting-edge; and

when thejentire saw-plate is moved in a curvilinear path parallel to the curvature of the cutting-edge, as in the second example given, the taperin thickness will be in direct-ions diametrically across the curves along which the grinding` takes place, or, in other words, in a direction at any given point of the curvature of the cutting-edge perpendicular `to the tangent ofthe curve at that point; but these dit'- ferences are immaterial so far as the practical uses of the saw are concerned. All this will more readily appear from the drawings annexed to this specitication, and forming part thereof, wherein- Figure 1 represents in cross-section taken through the grinding-line perpendicular to the direction ot motion ot' the grinding-surface the grindstoiie and presser-bar ot' a grindingmachine with a saw-plate between them. B is the grindstone, C the presser-bar, and x the saw. z is the apex of the angle between the presser-bar .and the grinder, and yz the line which ls coincident willi the platte of the saw-plate. y

Fig. 2 represents the extreme and middle positions of a saw with relation to the presserbarand grinder when ground bytheold method by moving` in a rectilinear patti.

Fig. 3 represents the extreme and middlepositions of a saw with relation to the presserbar and grinder when ground according to my new method by a movement similar to that of one member ot' a parallel ruler.

Fig. 4 represents the extreme and middle positionsofa saw with relation to the presserbarand grinder when ground accordingl to my new method iu the way which I prefer.

In each of the Figs. 2, 3, and 4 the broken line w fw', ruiming lengthwise of the presserbar C, indicates the position ot' the grindingline.

Fig. 5 represents the flat side of a crosscntsaw, with broken lines indicating the direction in which the grinding proceeded thereon by the old method.

Fig. 6 represents the same side of a crosscut saw, with broken lines indicating the direction in which the grinding has proceeded thereon by my new method.

Fig. 7 shows in cross-section the relative dimensions of a crosscnt-saw of ordinary size, taken at its middle, the saine being 14 wire gage vin thickness at the cutting-edge and 18 wire gage at the back.

Fig. shows the relative thickness of such a crosscut-saw at the ends when ground by the old method, the same being,r 16 wire gage -at lthe cutting-edge and 18 wire gage at the back.

Fig. 9 shows the relative thickness of such a size of crosscut saw at the ends when ground by my new method, the saine being 14 wire gage at the cutting-edge and 16 wire gage at the back. The wire-gage thicknesses of the two saws in various parts of ltheir length are further indicated in Figs. 5 and 6, respectively.

Fig. l() representsa plan view of a grindingmachine embracing improvements which I have invented for antoiiiatically putting into practice my new method of grinding crosscutsaws but for the bettershowing of these parts certain mechanism for adjusting and holding the presser-bar is'omitted in this view.

Fig. 1l is an end elevation of the machine, viewed when looking toward the broadside of the grindstone.

Fig. 12 is a side elevation viewed when looking toward the edge of the grindstone and nearest the teed-rolls between which the sawplate is tirst introduced.

Like parts ot' the machine in the different figures are designated by the same letters.v

A indicates the upright supports for the feeding and guiding mechanism. B is the grindstone; U, the presser-bar, which holds the saw-plate down upon the stone during the grinding operation; D, the driving-pulley for the feeding-rolls, a b b c c', a train of gears intern'iediate between the driving-pulley and the feeding-rolls; d d', shafts of upper feedingrolls; e e', shafts ot'lower feeding-rolls; fgj"g,

gears upon the shafts of the upper and lower l teeding-rolls, respectively, by which they are driven together; h i, forward pair of feedingrol'ls, which tirst act upon the saw-plate; h t7", rearward pair of feeding-rolls.

E is a yoke-shaped frame containing the bearings for the shaftsot' the feeding-rolls, and F is a frame of similar shape, in which the driving-pulley l), the intermediate gears, a b

b. c c', and the rear ends of the upper feeding- The two frames E roll shafts, d d', are hung. F are supported upon bars G G', to which they are fastened by set-screws. The bars GG slide in bearings l7c l It l', which are supported by the uprights A, so that by means ot thelever H,'wnich has its fulcrum at m in the stationary bar I, and is connected to the yoke E by a pin, a, working in aI slot, thc two yoke'- frames E F, with the feeding-rolls h t' h t" and all their driving-gear, may be moved toward and from the grindstone at the will of the operator.

o o are links which hold together the projecting ends of the shafts of each pair ot' upper and lower feeding rolls to prevent them from springing apa-rt unduly when the saw-plate is passed between them. l

J J J are guides against which the cuttingedge ot' the saw-plate is triade to bear in its progress through the machine, and which cooperate with the feeding-rolls to give to the saw-plateacurvilinearmovementsubstantially conforming to the general curvature of the cutting-edge.

K is a brace connecting the upper ends ot' the upright portions of the frame of the machine, and snpportingthe bearings ofa shaft-,19, on which is a hand-wheel, q, for regulating the position of the presser-bar C. This shaftp has upon it two bevel-gears, r t", which mesh into other bevel-gears, s s', respectively, on the upper ends of screw-rods t t. These latter turn in nuts u u,attached to slides ti fu', which carry the pressenbar C between them. The end of this presser-bar which is toward the end of the l machine opposite to that containing the driving-pulley is jointed to its slide in such manner as to enable it to be set at an inclination with the grinding-surface corresponding to the desired taper of the thickness of the saw-plate.

In machines of this kind heretofore used for grinding -crosscut-saws the two sets of feeding-rolls have been parallel to each other and substantially perpendicular to the plane ofthe grindstone, so that they have always fed the saw-plate over the grimling-surface in a recti linear path. On the otherhand,1 have so organized the machine that the two sets of feed-Y -ingerollcrs have their respective axes inclined to. each other, so that by their conjoint action upon the sawplate they will move it in a curvilinear path substantially conformingr to the general curvature of the cutting-edge of the saw. To accomplish this result in the best manner, the axes of each set of feeding-rollers should be perpendicular to the tangent ofthe rurve ofthe path of movement to be given to the saw at the point where such curve passes between the rollers, so that, for instance, in case thecurve of the path of movement were an arc of a circle, a plane passing through both axes of either pair of feeding-rollers would cut such arc in the direction of a radius thereto at the point of intersection.

lt will be readily understood that in order to have a set -ot feeding-rollers on each sideof the line where the grinder acts they must necessarily be placed far enough apart to enable the lower roller ot' each pair to lie below the plane which is tangent to the grindstone atits grinding-line, and hence while either end of the saw-plate is passing` across the space inter.- vening between the feeding-rollers on opposite sides of the grinding-line there needs to be, in addition to the single pair ot' feeding-rollers then acting upon the saw-plate, some auxiliary means for insuring' its movementin the re quired curvilinear path, For this purpose `I have provided the stationary guides hereinhefore'descrihed with surfaces for the cuttingedge if the saw-plate to-bear against, both in front of the forward pair of feeding-rollers and alsobetween those and the rearward pair,s that while ei ther set offeeding-rollers, acting singly, tends to move the plate in a direction at right angles to its axis, such tendency may be constantly curbed and the required curvilinear movement produced by keeping the cuttingedge of the saw-plate against the guides. The same result might be effected by providing an additional pair of feeding-rollers outside of each of those shown and described,and having their respective axes in like manner perpendicular to the tangent of the curve of the path of movement to be given to the saw-plate at the point where it passes between them; but my invention of the new crosscut-saw herein described is not limited by the specific character of the mechanism which may be employed for producing the same, the prime object being to eliminate certain practical detects consequent upon the old method of grinding in straight lines from end tocnd of the saw-plate; and the advantages of construction begin to be measurably obtained in straight saws as soon as the grinding takes place along curves which begin to approximate to the contour of the general curvature of the cutting-edge of the saw-plate, whatever may be the mechani- .cal means employed for effecting such modeof operation, so that although in order toinsure complete uniformity in the thickness of the cutting-edge of the saw-plate the direction of the grinding should perfectly conform to its curvature, yet the saw will be substantially made by any form of such curvilinear grind ing as constitutes a material departure from the old way of straight grinding.

The improvements which I have invented in machinery for grinding crosscut-saws according to my improved lnethod of grinding, which I have herein described for the purposes of illustrating my invention herein claimed, I reserve as the subject-matter of an application for a separate patent.

What I claim as my invention is- As a new article of manufacture, acrosscutsaw otsubstantially uniform thicknessthroughout the length of its curved cutting-edge, and of gradually-diminishing thickness in the direction ofits width from cutting-edge to back.

v GEORGE F. SIMONDS.

Witnesses:

J oHN SIMoNDs, Gao. P. WARD.

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