US 1320985 A
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Description (OCR text may contain errors)
F. C. BRIGHTMAN.
APPLICATION FILED JUNE L 1918.
1,329,985., Patented Nov. 4, 1919.
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FRANK C. BRIGHTMAN, OF NEW BEDFORD, MASSACHUSETTS.
Application filed June 7, 1918.
To all whom it may concern:
Be it known that I, FRANK G. BRIGI-ITMAN, a citizen of the United States, residing at New Bedford, in the county of Bristol and State of Massachusetts, have invented new, and useful Improvements in Drill-Points, of which the following is a specification.
This invention relates to drills and more particularly to the point of the drill, an object being to provide a point for use in drilling into soft metal, hard rubber, asbestos and the like, which will produce a smooth hole. Another object is to provide a drill having a point which will not choke and which will minimize the danger of breakage when the drill is turned backward, the formation of the point also especially adapting it for use with oil when required, as in boring into hard metals, the point retaining the oil better than the ordinary drill point;
Other objects and advantages of the invention will appear as the following description is read in connection with the accompanying drawings, in which;
Figure 1 is a side elevation of a twist drill provided with a point constructed in accordance with the invention;
Fig. 2 is a bottom plan view of thesame.
Referring to the drawings in detail wherein like characters of reference denote corresponding parts, the drill which is shown at 10 is of the twist type having opposite spiral grooves 11 extending throughout its length and a beveled point 12.
The invention resides in diametrically opposite sides. tween the spiral grooves of the drill be- 11 additional Specification of Letters Patent.
providing upon Patented Nov. 4, 1919. Serial No. 238,762.
grooves 13, the latter being of novel formation. The grooves 13 are V-shaped in cross section and extend inwardly toward one another in close proximity to the point of the drill, the walls 14 of the groove flaring outwardly, so that the widest point of the groove is at the periphery of the drill. The grooves 13 extend upwardly along the shank becoming gradually shallower so as to ter1ninate a short distance above the point of the drill as shown at 15. The walls 16 of the grooves 13 gradually converge from the point of the drill to the point 15, so that the edges of the grooves 13 define a substantially inverted V shaped pocket for the retention of a suitable lubricant.
By constructing the point as above described, there is produced a drill which will out a clean hole, clear itself, require less power for operation and will also hold oil, also it is desired that it be understood that the drill is not intended for an oil drill.
aving described the invention, what is claimed is The combination with a twist drill having spiral grooves and a beveled point, and relatively shallow V-shaped grooves formed in the periphery of of the spiral grooves, said grooves being relatively short in length and deepest adj acent the drill point with their sides and bottom converging at their opposite or inner extremities to provide pockets at the point of the drill. a
In testimony whereof I affix my signature.
FRANK o. BRIGHTMAN.
Gonies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.
Washington, D. O.
the drill between the edges