US1428415A - Drill bit - Google Patents

Description

J. J. BROSSOIT.

DRILL BIT.

APPLlCATlON FILED MAR. 22. 1921.

PatentedSept. 5, 1922.

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' A TTORIVEYS Patented Sept. 5, 1922.

' UNITE srras PATENT OFFICE.

JAMES JOSAPH BROSSOIT, 0F SALT LAKE CITY, UTAH.

DRILL BIT.

Application filed March 22,. 1921. Serial No. 454,376.

of Salt Lake City, in the county of Salt Lake and State of Utah, have invented a new and Improved Drill Bit, of which the following is a full, clear, and exact descrip- This invention relates to drills, and has particular reference to a new and improved cutting surface for drills.

An object of the invention resides in the provision of means whereby the cutting surface of a drill shank or holder may be readily removed to be sharpened and be readily replaced.

Another object resides in the provision of a simple and eflicient means whereby the removable cutting surface may be attached to the drill shank very readily and be firmly locked therein.

A further object resides in the particular construction and arrangement of parts which are hereinafter described and claimed and shown in the accompanying drawin s.

In arts where drills are used, especiaIly in mining and in rock' drilling, it has been hitherto necessary to provide a great number of drills, for the simple reason that during their operation a certain percenta e of the drills had to be constantly out 0 use to be resharpened. This necessitated the expenditure of considerable time and money and the waste of a certain percentage of the drills from actual use during the time they were withdrawn for this purpose.

My invention resides particularly in providin a cutting surface or portion of the drill s ank removable in a' simple and ready manner so that a number of them can be carried around, for instance in a miners pocket, and be placed in the shank as others are removed to be resharpened. This eliminates the necessity for having a larger number of drills than are actually in constant use, and merely necessitates having the reuired number of cutting portions on hand. It is a- .simple matter to take these small cutting portions and have them sharpened as deslred.

The invention is shown in the drawings, of which- Figure 1 is a side elevation of the drill shank and cutting portion parts being broken away;

Figure 2 is a section taken on the line of Figure 1; Figure 3 is an inverted plan view of 1; j 1 ;igure 4 is a plan view of the r taining p a e' Figure 5 is a partial section of a modiijied form of drill shank and cutting surace.

The preferred embodiment of my invention, as shown in the drawings, comprises a drill shank 1 the lower surface of which is provided with a groove 2 having tapered side walls 3. In this groove 2 a cutting portion 4 is disposed having similar tapered side portions and a cutting edge 5. In-- specting the inverted plan view shown in Fig. 3, it will be observed that the longitudinal lines 6 and 7 indicating the abutting edges of the cutting portion 4 and the groove 2, are tapered and wedge shaped. Between the upper face 8 of the cutting portion 4 and the surface of the groove 2 is a retaining or fastening plate 9.

The drill shank 1 and the cutting portion 4 are both of hard steel, whereas the retaining plate 9 is made of some softer metal. When the cutting portion 4 is to be placed into the drill shank 1, the retaining plate 9 is placed in the position shown in Flg. 2 and the cutting portion is then slipped into the groove and becomes wed ed therein, due to the tapered ed es 6 and 5 above mentioned. As shown in I ig. 1, one upper edge of the cutting portion 4 is provided with a beveled shoulder 10, and a slmilar beveled shoulder 11 is provided on the shank. When the cutting portion 4 is in position, the ends of the soft metal of the retaining plate 9 are ham-. mered down, as shown at 12 in Fig. 1, so as to lock the cutting portion 4 in position. The fact that the surfaces of contact between the retaining plate 9 and the shank 1 and the cutting portion 4 are between soft and hard metal makes this such a contact as will insure the proper amount of friction therebetween to hold the portions together, in addition to the other retaining means mentioned above.

In Fig. 4 is shown a view with the retain-- ing plate 9 tapered in accordance with the taper of the groove 2 above mentioned.

In Fig. 5 a cutting portion 4 quite similar to the one above mentioned is provided having in its upper surface near one end thereof a recess 13 with which the lower end 14 of a lock pin 15 pivoted at 16 in a groove 17 on the shank 1, is adapted to engage. When this engagement occurs, a pin 18 is driven sharpened. They are preferably made of drop-forged metal, are small and light. and may be carried on the person without inconvenience. This invention will be of great advantage in many operations, eliminating the distribution of the steel throughout the mines. By means of this invention it is not necessary to remove the drills from the place of working.

What I claim is:

1. A drill having a shank portion provided with a tapered recess in its lower edge, a similarly tapered cutting edge adapted to be disposed in said recess, and a retaining plate disposed between the cutting portion and the inner face of the recess, said plate being of soft metal the ends of, which are adapted to be hammered to lock the cutting portion in the recess.

2. A drill comprising a shank portion having a recess therein, said recess being tapered vertically and longitudinally, a cutting portion adapted to be inserted in. said recess and provided with similarly tapered faces, said shank and cutting portions being of hard metal, a retaining plate of softer metal disposed between the inner faces of the cutting portion and the recess, a beveled surface on the shank at one side, and a beveled surface on the cutting portion at the other end, the ends of the soft metal retaining plate adapted to be hammered to engage these beveled edges and lock the retaining plate and the cutting portion in the recess.

3. A drill having a shank portion provided with a recess in its lower edge, a cutting edge or tool disposed in said recess,-a retaining plate disposed between the cutting tool and the shank portion, and means on' said plate for locking the cutting tool in the recess.

4:. A drill having a shank portion provided with a recess in its lower face, a cutting tool to be disposed in said recess, and means disposed entirely between the bottom of the recess and the adjacent .face of the cutting tool to lock the tool in the recess.

5. A drill comprising a shank portion having a recess therein, said recess being tapered vertically and longitudinally, a cutting portion disposed in said recess and provided with similarly tapered faces, a retaining plate of soft metal disposed between the inner faces of the cutting portion and the recess, an upwardly beveled surface on the shank at the small end of the tapered recess, and an outwardly beveled surface on the cutting portion at the larger end of the recess, the ends of the soft metal retaining plate being distorted by hammering to engage these beveled edges andlockthe retainmg plate and the cutting portlon in the recess.

JAMES J OSAPH BROSSOIT.

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