Two alternative techniques make it possible to remove core-drill debris more rapidly and efficiently than was previously possible. Either technique is a vast improvement over the prior art. For industries in which ultrasonic core drills are used, these two techniques are expected to result in savings of time and money.

Typically, an ultrasonic core drill includes a diamond-coated coring tool that vibrates vertically at a frequency of 20 kHz. The drill can be used dry or with a coolant. The drill generates debris that often becomes trapped in the coring tool. In the situation that prompted the development of the two present techniques, technicians were having difficulty cleaning a coring tool. In order to clean the tool, they had to stop the drill, remove the tool, and use a thin, stiff wire to push out the trapped debris or, if necessary, pick the pieces out by hand. The procedure was tedious. Inasmuch as it is necessary to recalibrate an ultrasonic drill each time it is disassembled and reassembled, the task of cleaning was all the more time-consuming.

The two present techniques make the task of cleaning the coring tool easier and faster. The first technique makes it possible to leave the drill in place during cleaning — a decided advantage in that the need for recalibration is eliminated. To utilize this technique, the tool must be modified first. Two slots are machined on opposite sides of the coring tool, creating a convenient outlet for trapped debris and providing technicians with an easy way to visually discern the buildup of debris. After the tool has been modified, cleaning is as simple as using two pins to push the debris out through the slots.

The second technique involves the use of air pressure to push out the trapped debris. The coring tool is removed from the drill and mounted on a pressure regulator. A vacuum hose is attached to the bottom of the drill to vent the debris safely into a receptacle.

This work was done by Joseph J.Gervais of Rockwell International for Johnson Space Center. For further information, contact the Johnson Commercial Technology Office at (281) 483-3809.

NASA Tech Briefs Magazine

This article first appeared in the January, 2002 issue of NASA Tech Briefs Magazine.

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