Ronald C Douglas

US Patent:

20170043416, Feb 16, 2017

Filed:

Feb 17, 2016

Appl. No.:

15/045610

Inventors:

Ronald DOUGLAS - Mahwah NJ, US

International Classification:

B23B 51/04

Abstract:

A mandrel assembly for attaching a hole saw and a pilot drill bit to an electric drill is disclosed. The mandrel assembly has a “self-clearing” feature that removes the “plug” without removing the mandrel from the drill chuck. The mandrel assembly includes a threaded shaft having a first end for attachment to a drill chuck, and a second end for receiving hole saw. The hole saw has a base disposed toward the chamfered end with the base having an opening therethrough and an ejection rod disposed substantially parallel to the threaded shaft between the chamfered end and the base. The ejection rod matingly engages and passes through the opening. When the drill bit is reversed, the ejection rod enters the interior space of the hole saw and clears the “plug” from the interior space of the hole saw.