The invention relates to a perforator assembly (10) for drilling bone tissue, comprising a drive shaft (12) having a rotation axis (t), a chipping head (16) having the same rotation axis (t), a drill head (14) arranged coaxially inside the chipping head (16); a first connecting profile (20) is provided at a proximal end (18) of the drill head (14), and a second connecting profile (24) is provided at a distal end (22) of the drive shaft (12), and the drill head (14) is arranged so as to be displaceable with respect to the chipping head (16) along the rotation axis (t) between a proximal position and a distal position, and in the proximal position the second connecting profile (24) at the distal end (22) of the drive shaft (12) cooperates with the first connecting profile (20) such as to transmit rotational motion from the drive shaft (12) to the drill head (14), and in the distal position the first connecting profile (20) at the proximal end (18) of the drill head (14) and the second connecting profile (24) on the distal end (22) of the drive shaft (12) are disengaged characterised by that a first magnet (54a) is arranged in a closed off cavity (50) at the proximal end (18) of the drill head (14), and a second magnet (54b) is arranged in a closed off cavity (52) at a distal end (22) of the drive shaft (12) such that same magnetic poles are facing each other.