Multiple mode chuck

A method for the insertion and extraction of a plurality of tool bits from a quick-release chuck assembly, the method comprising:

• inserting a first tool bit into a longitudinal hub bore of a hub, the longitudinal hub bore having a first profile;
• contacting a plunger with the first tool bit, the plunger being slidably disposed within the longitudinal hub bore;
• displacing the plunger from a first plunger position to a second plunger position;
• extracting the first tool bit from the longitudinal hub bore, whereby the plunger is disposed from the second plunger position to the first plunger position;
• inserting a second tool bit having a smaller profile than the first tool bit into a longitudinal plunger bore of the plunger, the longitudinal plunger bore having a second profile smaller than the first profile of the longitudinal hub bore;
• and
• extracting the second tool bit from the longitudinal plunger bore.

In a quick release chuck assembly of the type in which a hub has a forward end and a longitudinal hub bore disposed into the forward end of the hub forming a bore wall and terminating end face, the longitudinal hub bore adapted to receive and retain a first tool bit having a first cross-sectional profile, the improvement comprising:

• a plunger slidably disposed within the longitudinal hub bore, the plunger having a front end proximate the forward end of the hub and a rear end, the plunger being in fixed rotational engagement with the bore wall of the longitudinal hub bore;
• a longitudinal plunger bore disposed into the front end of the plunger, the longitudinal plunger bore adapted to receive a second tool bit having a second cross-sectional profile smaller than the first cross-sectional profile of the first tool bit;
• and
• an elastic body disposed between the rear end of the plunger and the terminating end face of the longitudinal hub bore, the elastic body acts to bias the plunger toward the forward end of the hub to a first plunger position.