US90759A - Improvement in auger-bit - Google Patents

Description

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Laws Patent No. 90,759, dated Jun@ 1, 1869.

IMPROVEMENT IN AUG-ER-BILI.

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

To all ywhom it may conce/rn:

Be it known that I, H. G. LEWIS, of Essex, in the county v. of' Middlesex, and State of Connecticut, have invented a new Improvement in Auger-Bits; and I do hereby declare the following', when taken in connection with the accompanying drawings, and the letters -of reference marked thereon, to be a full, clear, and exact description of the saine, and which said drawings constitute part of this specification, and represent in- Fi/gure 1, an end view.;

Figure 2, a side view;

Figure 3, a side view, turned one-fourth around;

Figure 4, a section on line a: x; and in Figure 5, a section on line y y.

This invention relates to an improvement in that class of boring-instruments known to the trade as auger-bits.

Heretofore, this class of bits has ,been formed by fitting the spur in a separate piece, which often, by

hard use, breaks out from the body o f the bit, and' thus ruins the instrument; and, further, these bits have been formed from a bar of metal, so thick that the chips' are all forced outward, and compelled to lI will proceed to a description thereof, as illustrated in the accompanying drawings.

The bar from which the bit is to be formed is rst drawn dat upon the outside, and convex upon -the inside, as seen in fig. 4, and so as to form a sharp edgey both above and below; the thickness of this bar being only so much as, when twisted, will leave an opening, A, through the centre, as seen in fig. 5. This bar- I form about twice the width of the usual bar, that is to say, about equal to the space in the twist. an opening is formed entirely through the centre of the bit.

At the lower end the bar is turned down, and upon its centre is formed a conical screw, a, and from the screw outward a cutter, d, is formed, from the cutter falling back upon a gradual incline to the opposite side, where the spur f is formed, and the incline continues beyond the spur until it dies out iu the twist, as seen in figs. l and 3. c

It is only necessary that the spur .be little longer, or project a little below the cutting-edge; therefore, by inclining from the cutter to the spur, it requires but little more metal than is removed, in forming this inclination to make the spur.

Thus, I have formed a most perfect single-twist A auger-bit; and having thus fully .described my invention, I do not, broadly, claim placing the spur upon a single-twist bit, upon opposite sides to the cutter, as such position is common landrwell known; but, as before stated, when so arranged, the spur has been formed separate from and fitted into a seat, prepared at that point to receive it.

What I claim as new and useful, and desire to se- Thus,

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