US66692A - James b - Google Patents

Description

@einen tetes etretQffire JAMES E. EMERSN, F TRENTON, NEW' JE tSll'Y.

i Letters ,Patent No. 66,692, dated-July 1.6, 1867.

IMPROVEMENT Iii SAWS.

TO ALL WIIOMVIT MAY CONCERN:

Beit ltnown that IJAMES E. EMERSON, ot Trenton, in the county of Mercer, and State of New Jersey, have invented certain new and useful Improvement i'n Saws; and I do hereby declare the following to be a full, clear, and exact description of the saine, reference being had to the accompanying drawing, which is made n part of this specification, and which represents u side elevation of a saw-blade, which, for the salte ol` convenience ot' illustration, has been made to exhibit several varieties of teeth.

The lirst part of my invention consists iu providing thc saw with apertures or perforations, a series or plurality of which extend consecutively and in a definite line from or near the throat or point of juncture of each pair of teeth, and which subserve the purpose of facilitating the sharpening ot' the saw, as will be hereinafter more fully explained. The second part' of my invention consists in a novel method of forming the saw with clearing-teeth, in connection with chambers or openings in the blade, for the purpose ot' removing the sawdust from the korf, and cutting oi the ridge which remains at thc base of thekerf in consequence of the set position of the teeth.

In order that others skilled in the art to which my invention appertoins may be enabled to fully under stand and use the same, I will proc-eed to describe itin detail, in connection with the accompanying drawings.

The ligure is a representation of usingle blade, having a set or large teeth, a, and of small teeth b, such as are formed on the blades ot' crosscut or reciprocating saws, and a circular or Islitting sawtooth, e. It is oi' course to he understood that this embodiment of the several varieties of teeth in a single blade is merely to condense the illustration, the individual saws, as manufactured, necessarily embracing but one hind of workingtooth. d cl d represent apertures, which are punched through the thickness of the blade or otherwise produced therein, a plurality of which apertures extend in a definite line or series from the point of juncture between each pair of teeth toward the back of the saw-blade. 'lhe object and utility of these apertures will be understood from the following explanation: Under thc method ol construction heretofore most commonly adopted, it is necessary to bring the saw-glimmer into requisition as often as the teeth need sharpening, the operation .of said instrument involving considerable dificulty, and the instrument itself being in many instances unobtainable. The use of the gummer is rendered necessary, because the tile itself cannet be made to cut with the required precision, or form the curvature at the throat of the teeth to obviate cracks or fractures. It will be seen that in my case the apertures cl, being taken as a guide, enable the file to be effectively applied with facility. To enable the metal between the apertures d to be readily removed by the file, IY propose to soften rhis'part of the blade through the agency of heat, which may also serve as a medium for toughening the blade in the region of said apertures. The apertures d may. be made in various forms. In circular saws the apertures d should be disposed in a line corresponding to the direction 'in which the teeth wear and are sharpened, as shown in the drawing. I am aware that John Lippincott obtained a patent on the thirteenth day et' March, 1866, for a saw in which is provided a slot or indentation, having parallel sides, and extending into the blade below the root or termination of the inclined side of the teeth, for the purpose of servingvas a guide in dressing the saw with a. tile. y'this method a large portion of metal isrelnoved, and the teeth are made liable to yield or vibrate, and hence operate'inetliciently. In my saw each portion of metal between the apertures d adds to the strength and rigidity of the teeth. e e represent chambers or openings formed at suitable intervals in the saw-blade, and i extending into the latter from the extreme cutting-edge to a point considerably beyond the hase of the teeth, said chambers terminating in a curve, to avoid. liability of fracture. These openings or chambers e divide the teeth into sets of any desired number, as may be properly eoicuiated in constructing the saw, cach of such sets being concluded by a half` tooth,f, the point of which stands out of line with and somewhat nearer the longitudinal centre of the saw than the points of the working-teeth. This halt toothf serves not only to remove the ridge at the base of the korf, but also clears thc korf of sawdust, and deposits the same in the chamber c, which carries the dust out of the kort' and drops it. The clearing-toothf has straight or rectilinear sides, so that in dressing the same the relation of its point to the points of the working-teeth will always be uniformly mointained. It is also well braced and steady in operation, from the fact elf beingjoinod nt one side to the section of the saw upon which a set of 'the working-teeth are formed. I um aware that it is not new to form a hooked clearingftooth on the toothed sections of a saw, euch feature being exhibited in a withdrawn application, tiled by George R. Atkins, in 1857 but iu this oase the clearing-tooth is not susceptible of dressing er tiling without changing the relation between the points' oi' the clearing and working-teeth to such an extent ns to materially impair or altogether destroy the eliiciency of the saw. K i

Having thus described my invention, what I claim as new hcrein',^and desire to secure by Letters Patent, is-

The provision in u saw of apertures d, for facilitating dressing or sharpening, substantially as described.v

. J. E. EMERSON.

Witnesses:

Cnas, D. Snrrn, Cms. A. Pnr'rrr.

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