Self-Tightening Rotary Tool Holding System

A tool holding system comprising:

• a first cage member including a first plurality of elongated slots, each of the first plurality of elongated slots having a first end portion which opens to a first shank receiving opening defined by the first cage member, and a second end portion which does not open to the first shank receiving opening;
• a plurality of roller members, each roller member of the plurality of roller members movably positioned in a respective one of the first plurality of elongated slots;
• and
• a roller carriage including a carriage opening aligned with the first shank receiving opening, and a plurality of generally cylindrical passages, each of the plurality of generally cylindrical passages (i) substantially parallel to the central axis, (ii) receiving a portion of a respective one of the plurality of roller members, and (iii) configured to prevent the respective roller member from moving circumferentially relative to the roller carriage while permitting the respective roller member to move radially relative to the roller carriage within a predetermined range.

A rotary power tool comprising:

• a first collar rotationally fixed with respect to an output shaft of a power tool and including a first shank receiving opening having a longitudinal axis;
• a second collar movable with respect to the output shaft and including at least one inclined outer surface;
• and
• at least one lever pivotably connected to the first collar and including a first end portion configured to engage the at least one inclined outer surface, and a cam located at a second end portion, the cam extending into the first shank receiving opening such that upon rotation of the output shaft in a first rotational direction, the at least one inclined outer surface is forced against the first end portion thereby forcing the cam toward the axis.