US Patent: 2,360,385
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| Drill
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Patentee:
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| Conrad A. Anderson (exact or similar names) - Milwaukee, WI |
| Manufacturer: |
| Not known to have been produced |
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Patent Dates:
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| Applied: |
Mar. 08, 1941 |
| Granted: |
Oct. 17, 1944 |
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Stan Schulz
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Description: |
| Lieber & Lieber - patent attorneys
This invention relates generally to improvements in the art of boring holes in diverse objects, and relates more specifically to various improvements in the construction and operation of drills especially adapted to form circular holes in metallic bodies or the like. t has heretofore been common commercial practice when drilling holes of relatively large diameter in rather small and portable metal objects or bodies, to utilize a stationarily mounted inverted twist drill and to rotate the objects about the central axis of the drill while suspended there above. One reason for this practice of inverted drilling, is to facilitate downward escape of the chips by gravity away from the zone of cutting, and this removal of the chip debris may be enhanced by forcing cooling and flushing liquid through one or more elongated passages in the drill, and against the work adjacent to the cutting edges. This cooling liquid will thereafter flow downwardly along the helical grooves of the twist drill and carry the chips with it. In order to provide these elongated liquid circulating passages extending throughout the length of the twist drill, it was necessary to form the circulating holes in the drill body before final twisting thereof, and this procedure would frequently cause the liquid ducts to offset and become distorted to such an extent that either free circulation was impossible, or the drill was weakened and would break. This was especially true in long twist drills, and another objection to these prior structures was the improper location of the discharge orifices of the cooling liquid passages, which were usually disposed between the heels of the cutting portions of the drill and the work, and thus prevented free escape of the liquid and precluded proper flushing of chips away from the cutting edges. It was moreover difficult with these twist drills, to produce drilled holes having several adjoining sections of different diameter, and the regrinding of the twist drills for such purposes also introduced serious problems due to grinding difficulty and waste of stock. The prior liquid cooled twist drills were expensive to construct and to maintain, requiring considerable attention to keep them in proper operating condition, and could not be varied in diameter to meet slightly different conditions of use. It is therefore an object of my invention to provide an improved drill especially adapted for inverted operation, which is simple and durable in construction and highly flexible and efficient in use. Another object of the present invention is to provide a new and useful drill assemblage so formed and having liquid circulating passages provided with discharge orifices so directed, that chip debris will be most effectively broken up and removed from the cutting zone by liquid flushing action. A further object of this invention is to provide an improved drill structure having a readily renewable cutting portion capable of effectively producing single or multiple diameter holes, and which can be conveniently resharpened and maintained in operative condition with minimum attention and waste of tool stock. Still another object of the invention is to provide a new drill construction having liquid circulating passages and ducts therein which can be readily formed, and in which the cooling and flushing liquid can escape freely from the cutting zone or zones. An additional object of my invention is to provide an exceptionally strong and accurately formed drill assembly which will withstand severe usage, which can be manufactured at moderate cost, and which is especially adapted for use while fixedly held in an inverted position and cooperating with revolving work suspended there above, but which can also be positively rotated and caused to cooperate with stationary work.
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