US95052A - Improvement in saws - Google Patents

Description

JosEPH H-.SMITHIA-ND ELIYJiAH e. PECKHAM, or ToLED'aoHid llftetiters .Patent No, 95,052, dated September 21, 1869.

IMPROVEMENT IN SAWS.

The Schedule referred toy in these Letters Patent and making .part of the same.

To all whom it may concern: -r

Be it known that we, JOSEPH H. SMITH and ELI- JAH G. PEGKHAM, of Toledo, in the countyl of Lucas,`

`and State of Ohio, have invented a new and useful Improvement on Saw-Teeth; and' we do hereby de# clare that the following i s a full, clear, and exact description thereof', reference beinghad to the accompanying drawings, making part of this specication, in which,- t Y Figure 1,` plate 1, is a side view of a portion of a saw-blade having the improed saw-teeth formed on it.

Figure 2 is an end view of iig. 1.

Figure 3 is an edge view of the saw-teeth;

Figure 4, plate 2, is `a diagram illustrating an old form of saw-teeth, in full lines, vand showing, by the aid of dotted lines, the manner-of producing our improved teeth.

Similar letters of reference indicate 'corresponding parts in the several gures.

lhis invention relates toan improvement on the l construction of teeth forcross-cut saws and consists in alternate pairs ofv straight cutting-teeth, whichare separated individually by a narrow straight slit, and which terminate'at their ends in double-bevelled cutting-edges, in combination with an intermediate single raker or' clearingftooth, whichv has obtuse angles on' opposite edges, and a central acute clearing-point, as willl be hereinafter explained.

We are aware that cross-cut saws have been made hefore'our invention with single clearing-teeth arranged between pairs of cutting set-teeth, the latter teeth being separated individually by narrow slits extending into the saw-blade only as far as the bases of the clearers,'and we do not claim, broadly, such an arrangement of set-teeth and clear-ers as our invention.

The followingdescription of our improved saw-teeth `will enable others skilled in. the art to understand their construction and operation.

In the accompanying. drawings, figs. l and 3, we have represented a portion-of a saw-blade having formed upon one edge three pairs of cutting setf teeth and three intermediate singlel rak'ers or clearing-teeth.

,` The set-teeth cnt `downthe sides ci' the kerf, while ,the clearers remove the ridge left between the two parallel cuts made by the set-teeth.

In the constr'uction of this class of cross-cut saws, it is important- First, -to lprovide free clearance for the dust, to preventit accumulating between the teeth and about their cutting-edges;

Second, to prevent gumming, by cutting narrow slits into the blade at those points where'the gumkerf will be cut before the clearers scrape or cut Ofi the ridge;

Fourth, 'to employ clearers which will not collect the dust, nor interfere with the` cutting of the stteeth;

Fifth, to obtain as much space as possible betweenv a given number of teeth in a given length of' blade, without weakening the teeth; and

Sixth, to so shape the teeth that they can be sharpened and kept sharp with the least amount of labor and removal of metal.

.a a, represent the cutting or set-teeth, which are'A spacedin pairs, with a narrow parallel slit, d, between the teeth of each pair.

These teeth a a. are straight, that is to say, their edges are parallel, and `terminate in idouble-bevelled or angular cutting-points, which are sharpened and set as shown in the drawings. l,

By making the edges of the teeth a (t parallel or perpendicular to the length of the saw-blade A, and producing the cutting-edges of ylievelling each tooth equally on each edge o, triangular cutting-points are formed, which can be regularly sharpened.

Between every two pairs of cutting-teeth a a, and equidistaut from the centres of the slits d, is a tooth, b, on each side of which a space, e, is formed, which is carried further into the saw-blade than the slits d.

The spaces e e terminate, along their edges next the back of the'saW-blade, in semicircles,which, as they do .not present angles, will prevent an laccumulation of sawdust in said spaces. t a Each clearing-tooth b is tapered from Aits base to the `points i i, and from these points or to the acute angle s, the edges j' f are abruptly bevelled, so as to .leave obtuse angles at the junction of the edges f (1, on each sidc ofthe tooth.

The teeth b, thus constructed, will cut or vclear in the forward well as backward movements of the saw, and they will not clog with sawdust, like thedouble-edge clearers hitherto used in combination with pairs of set-teeth.

In sharpening the clearers b, the file is applied upon the short bevelled edgesV f, and a very small amount' ofthe metal is required to be removed to effect Athey sharpening, while, at the same time, the tooth is not black lines show a pair of set-teeth separated by a slit,

which leaves one Yedge of each set-tooth perpendicular to the. length of the saw-blade, while the opposite edge of each set-tooth is hevelled from its cutting-point to its base.

The olearers, which are between the pairs of setteeth, are of a, V or acute angular shape. In filing these teeth, gunimiug cannot be prevented, and n eomparatively large amount of metall must be removed by the le to keep the teeth sharp. i

By removing the metal as indicated by the-dotted lines, we form setFteeth with parallel edges, we round out and deepen the spaces on the opposite sides of the elenrers, and we reduce the width of tlie'elearers, so that the most inexperienced 'hand can Sharpen the teeth without gumming.

As a greater amount of space is required between the elearers and set-teeth than is required between each pair of set-teeth to prevent clogging, it will be seen tba-t we do not cut the slits d `into the blade as ir as the spaces e extend, but leave such an amount of metal et the bases of the set-teeth as will afford them all the strength required.

Having described our invention, v

What We claim as new, and desire te secure by Letters Patent, is*- j The snw-bmle, which combines in its construction pairs of teeth, separated below their cutting or sharpening-bevel, and an intermediate single clearingtocth, which has nn angle, t, en each of its sides, substantinlly as described.

JOSEPH H. SMITH. ELIJAH G. PECKHAM.

Witnesses:

AVERY S. HILL, JAMES BADDEL-r.

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