USRE3703E - Saw-teeth - Google Patents

Description

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JOHN Loneitor BUGKINGHAM VILLAGE, QUEBEC.

Letters Patent No. 84,365, dated Nvembe-r 24, 1868; reissue No. 3,703, dated NoremfberrZ, 1869.l

narnovnumw IN Bassenge saw-Tem They Schedule referred to in these Letter! Patent and making part of the name.

. To all whom it may concern:

Be it known that I, JOHN LOUGH, of the village of Buckingham, in the county ofDttawa, in the Province of Quebec, millwright, beinga British subject, and a. residentof the Province of Quebec, have invented a new and useful Improvement in Saw-Teeth, and in the apparatus for forming the same and l dohereby declare the following to be a full, clear,and exact description ot'F the construction and Ioperation' of the same, reference being had to the aceompanyingdrawings, forming part of this. specification, and in which- Figure 1 represents a plar. 'view -cf saw-dressing machine;

Figure 2 represents a section of the same;

Figure 3 represents a side elevation of saw-tooth press.

Figure 4 represents a side elevationof ihe same,

with one side removed, and arranged for circular' saws.

Figure 5 represents a back elevation of saw-tooth press. f

Figure 6 represents 'details of me.

Figures 7 and `8 represent details of ordinary sawteeth.

Figures '9 and 10 represent details of improved sawteeth.

, ;Ehis invention has reference to the improvement.

in. the shape or form of l saw-teeth, either in straight or circular saws, and also in the apparatus necessary for ,forming the said improved teeth.

First, with reference to the form of the teeth. In the ordinary plan adopted for constructing and shaping saw-teeth, the teeth are iirst cnt out by dies. ,A taper steel bar isthen held on the under side of each tooth and hammered on, the opposite or upper side of the tooth. The efl'ect of this is to widen the point of the tooth on the npper side. The point of the tooth is then tiled to 'the required degree ot' sharpness and u set. V

The defect of this mode of swagingor'of widening the tooth, as described, is, that the under or cutting-side of the tooth remains narrow, whereas, by my improvement, this portion of' the tooth is widened at a point where such is actually required, inorder to efficient cutting when employed in sawing timber, thus reversing the ordinary condition or shape of the saw at this important point.l

Another defect in the ordinary forni of sett-ing the saw is also obriated by my invention. In place of treating each tooth separately by a hammer and tile',l 'y

a dressing-machine, extending over a considerable number ofteeth, or, indeed, over. the entire' number, ifreqnired, at one and the saine time, is employed,

' and the sanne treatment'extended to each tooth simultaneously, thereby avoiding any diiferencr,`alid creating complete uniformity.

The peculiar form' given to the lower or cutting;A side of each tooth is accomplished by passing the saw,

either straight or circular, through a peculiar appaia4 tus, the nnformed point of each tooth passing into a peculiar-shaped steel die, and pressure applied by a powerful lever, which has the efiect of making the tooth assume theshape of the die, or, in other words, the widened under cutting-surface before mentioned, each tooth of the saw being subjected, in turn, to this treatment.

When, after much use, the teeth of the saw become impaired or worn out, the saw is straightened and gnmmed, and pnt through the same process for widening the teeth, bythe employment ot' my apparatus.

In the drawings, similar ,letters of reference 1unncate corresponding parts.

a, figs. 7 and 8, is the ordinary form ot' saw-teeth, widened 'onthe upper side, as shown in the drawings, while "b, figs. 9 and 10, represents my improved tooth,

widened on the opposite or under side.

This part of the improvement being so clearly shown in the drawings, and while being of great importance, yet is of so simple a character as to require no further description, Iwill therefore proceed to describe that part of the apparatus used ihr Agiving the tooth the shape required.

It consists of two steel pla-tes c c, of the general form shown in figs. 3 and 5, bolted firmly together by screw-bolts d df The projection e, forming part of the plates referred, to, is providedy with a slotted space, f, for the reption ofthe saw g and guide-wedge key g, for holding the saw rmly in place against the die when being operated on.

-g is level', attached to the projection e of the plate c c by a strap', g, which is provided` with two y .mortises or apertures, for the reception of the ends of the two projections, and held in place by the` crosskey g.

Attached to this fever g is a double eccentric, g5, with an intervening space, as shown in lig. 5, for the reception of the gudefwedgc key y and back of saw. y. y-

This guide-wedge key g is held in place by a steel pivot, g, passing through it, aswell :ts-each of the l a pivot, g", working freely in the lever by means of the elongated slot,

two guidestraps h, and is attached to-thenfr by the Those curved connecting-straps are again attached, by a pivot, h5, to the outer end of a compression-bar, t', shown in gs. 3 and 4.' f

This compression-bar is of steel, with great strength, and is used for' pressing the point and underside of tbetootl. into the die,'to be presently described.

This compression-bar has the form shown in lig. 4, and works freely between the two steel plates c c, in a suitablei'ccess provided for. that purpose.

The inner end of this slot is circular,'and deepened, for the reception ofthe. circular flanged end 'of the compressimvhan which' tits and works accurately into it, both above and below.

A portion of the circular end of this compressionbar is removed, as shown at il, in liig. 4; A' square shoulder is thereby formed in the end of the bar; ad'- jacent to the saw-tooth, and which comes in contact with it, and presses it squarely into the die.

:A small groove is provided on the ,inner end .of the compression-bar, as indicated by-the fdtted :lines at fi, possessing'a width about equal to'thefthicknessefa saw. l The object of thisv groove isl to permit the passage of the teeth of saws with a small pitch.`

lt is a strong steel die, passing entirely thppngh both phi tes c c, in the position indicated in figs. 3, 4, and 5.'

The peculiar for-m of this-die is shown in iigf. t or near its centreit is providedwithabevelled check orrecess, k', as shown in the drawngs,.fqr receiving the tooth, and giving it the required shape.

l is a guide-strip, inserted between the two plates, and serves to steady the straight saw,` when scription is being operated.

When a circular saw is to 'be treated in this apparatus, the guide-strip 'l is removed, and the extension supporting-strips m, one on each side of the saw, attached' to the projections .e e of plates c c.

A wedge-key, n, passes through both of .the strips m m, and serves to keep the saw pressed closely. up against the die. l

I will now vproceed to describetbe apparatus enr- `ployed for the ncxtstep ln the operation of treating the teetl, and bringingl them to a uniform set. In figs. 1 and 2 will be seen drawings ofthe same, g represent-ing the saw as before, rest-ing ona straight bedplate, o, with a checkedsnrface at o', for the purpose of giving room for .tbe widened teeth of the saw, thus allowing the body of the saw a firm bearing on the bed-plate o.

A.' second or top clamp-plate, p, is placed on the up' per sideoi` the saw, and firmly secured to it by thescrew-clamp q.

ris a plane or file-holder, of any convenient length required. s

In a recess provided on its lower side .is placedan iron plate, s', attached to the'plane, and moved by s'etscrews t. l

To this movable plate s is attached, by suitable clamps, a file, n. y y,

c is a guide or gauge-strip, screwed to the sidel of the plane by screws' v', working in slots provided in the strip.

By this means tbe plane may be adjusted to any required thickness of saw, and, by the, use of the setscrews. t, the plane may 'oe adapted toany size of set. With the foregoing brief description of n lyjnventlon I in sawgteetb, and in the apparatus for forming the saine, I`will now proceed todescribe its operation.

" First, 'with reference to thesawteeth.

that dei ,By the use of my improvement, itisiascertained that plate, from the fact that each tooth cleans the out entirely through on each side, whereas the ordinary tooth does it only on one side.

to three times as long as the ordinary saw without being changed, land at the same time do from ten lto litteen percent. more work in an equal length of time. r

Considerable saving in time, and consequent vexf pense, is also had in dressing up my improved saw. Second, with reference to the operation of forming the teeth by the improved apparatus.

The apparatus being arranged substantially as described, the straight saw to be operated on is'screwed into two clamps, one at each end, the clamps being attached to a suitable bench. 'l

The connection between the apparatus-and the saw is eected by removing the strap g, and placingfxthe saw g between the twoplates cpc. This done, the strap g is again put in place, and held-there by the tapering'key g. The wedge ql is also introduc'ed, as shown in fig. 3.-

By the action of the lever g, the eccentrics g', and the wedge g1, the saw v i/ is moved forward until the tooth to be operatedv on comes into the bevelled check or recess It', and retained firmly in that position. Pressure is now-brought to bear ,on the tooth by means of the lever h., lstrap li, and compression-bart ingl the saw-tooth into the entire cavity ofY the bevelled recess'k, and thus ,give the required shape or forinto the tooth. This being done, the saw is re'- Yoperated on is removed from the recess, the apparatus succeeding tooth to drop into the recess It', when, by means of the lever la, the same process is repeated, and so on. All the teeth treated in the same die will,

therefore, possess uniformity of size and shape,l f

The next, and finishing operation, consists in placing the saw just't-reated on the.y bed-plate o, and attaching it firmly to the same by the top plate'p and clamp q. The tile u' and Vgauge-strip c are then properly adforth overthe teeth of the saw until their points are accomplished with great'exactness, on account of the plane or its iile resting on a considerable number of teeth at one and the same time, also governed 4by the adjusting-guides. l The operation being accomplished on onefside of the saw, the saw isreversed, and the opposite side, treated in like manner.

'When a circular saw is to be operated on, it may rest on its own axis, and have the apparatusfapplied to each tooth in succession by the employment of the .extension-pieces-m '111, -fig. 4, which 'are' adjusted to the size of the saw to be operated on, the `guide-piece shown nftig.,4.

By a slight modification of the'dressing-machine,

-figs. 1 and '2, the circular-saw teeth may be brought to a true line or set, by causing the saw to revolveon its axis, which, inl this case, will pass through the plates above and below.

As before stated, the apparatus heretofr'e employed point ot' the tooth, whilethe bar and hammer amused for widening the upper side of the trxyth. From this l tained.

, sans v the form of the, teeth gives greater freedom to 'the saw? My improved saw can beused in the' gate from two toa sulcient extent to force the material composlieved bymeans of the lever 71, dac., and the toothjust moved forward to a sullcient distance 'to enable the,

'justed on the plane, to snitthe "thickness and set of l the saw. This done, the plane is passed back and.

brought toa true line, which, by this process, can be l, tlg. 3, being removed to allowth'eteeth to pass, as

for forming saw-teeth consists, in sovfar as my knuffl edge extends, of a simple swage, taper steel bar,'and hammer, the swage heilig used for Widening the'very V' it is evident that uniformity o'inish cannot be ob- What 1 claim as my ,improvement or invention, is

the improvement in saw-teeth, and in the apparatus for forming the same, as follows: A 1. Widening saw-teeth on their under or cuttingface by pressure, substantially as and for th'e purpose set forth. I

2. Widening the saw-tooth at its under side in such a `manner that the expanded cutting-face thereby produced is parallel-sided, or in'the form lsubstantially as .shown in, iig. 10,- and as hereinabove described, for the purpose set forth.

3. The plates c c, when united by the bolts d d, and' provided with .theprojections e e and the arm h, and having betweenthexn the 'space f and the space for the compression-bar,` substantially as described.

2 4. In combination with said plates c c, constructed as above described, the lever h, pivoted at hl, the strap h, the compression-bar i, and the die k, all .operating together in the manner and for 4the purpose set forth.

5. In combination with said plates c c, constructed as above described, the wedge g, lever g, strap g, key, or equivalent;y g, eccentric g, and pivotsg 117 g', all operating together substantially as and for the purpose set forth.

' 6. The improved saw-dressing nmohne heroin described, oonsisting of the bed-plate o, top plate p,

lclamp q, plane r, iron -strap or flle-holdcr s, adjustable screws t, file u, adjustable strip 1:, and adjusting-screws v', all arranged and working together', substantially i'n the manner and for the purpose described.

' l JOHN LOUGH. Witnesses:

OHAnLns LEGGE, GHARLEsG. 0.'S1Mrsox.

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