Patent ID: 9399272
Filing Date: 2016-07-26
CPC Classification: B23B,B23Q,Y02P,Y10T

Claim Text:
1. A dust extraction device for a rotary power tool having an elongate rotating drill bit for operating on a work surface, said device comprising: a casing having an inlet and an outlet and defining an interior cavity, said inlet and outlet communicating with the interior cavity for permitting air flow into the interior space from the inlet to the outlet; and a fan element having a plurality of impellers and a central hub adapted for rotation within and independent of the casing for inducing air flow within the casing from the inlet to the outlet when the fan element rotates; whereby rotation of the drill bit results in air flow to remove debris from the work surface to the outlet without rotating the casing; wherein: the hub is adapted for engaging the drill bit in a manner that permits rotation of the hub as well as axial movement of the drill bit relative to the hub during rotation of the drill bit; rotation of the drill bit is transferred to the fan element via two opposing aligned pins that extend radially into a spiral flute of the drill bit; the fan element is articulated to the drill bit by means of an adapter comprising a generally cylindrical body having an axial bore dimensioned to accommodate a drill bit so as to allow unimpeded rotation of the drill bit within the adapter without undue slack; and said pins projected radially through a side surface of the cylindrical body of said adapter leaving protruding portions that project out of a side surface of the body and are adapted to engage arcuate recesses in the hub of the fan element.