Chuck Removal

Hi,
Any tips for removing the chuck from a Progress 1S pillar drill?
It has a knurled threaded ring above the chuck, which can screw up/
down by about 20mm, to tighten onto the top of the chuck or the bottom
of the quill. This looks as though it could be used to remove the
chuck - but is there a morse taper in the quill, or only a Jacobs
taper into the chuck??
Help!
TIA,
Alan.