My "Power craft"(Aldi)SDS drill had a 14mm bit jammed in the chuck. I was able to remove it as follows. (After unplugging from Mains) 1) remove black rubber collar, 2)push metal collar back, and prise out circlip . This should allow all these parts and spring to be slid off over the jammed bit, leaving shaft. Be careful not to lose the ball-bearings. (These hold the bit in place when in use). 3) If the bit cannot be removed at this point, protect the shaft of the drill with a piece of slit 15mm copper tubing, and grip it firmly in a vice. 4) Clamp a vice-grip type wrench tightly on to bit, striking this with a hammer, tap the bit out of the shaft. My bit came out after a few sharp blows. 5) Re-assemble, using grease to hold ball-bearings in position in holes in shaft, close the circlip to make it a tight fit. The drill seems to be OK so far. It was kill or cure. I am very happy with the job. I hope this helps some-one.
Jim Gil. June 2011, June 2011