Perforator for drilling bone tissue, comprising: - a drive shaft with rotation axis (t), - a drill head with the same rotation axis (t), - a chipping head arranged coaxially around the drill head, a first connecting profile is provided on a proximal end of the drill head, and a second connecting profile is provided on a distal end of the drive shaft and the drill head is arranged so as to be displaceable with respect to the chipping head along the rotation axis (t) between a proximal position and a distal position, and in the proximal position the second connecting profile on the distal end of the drive shaft cooperates with the first connecting profile such as to transmit rotational motion from the drive shaft to the drill head, and in the distal position the first connecting profile on the proximal end of the drill head and the second connecting profile on the distal end of the drive shaft are disengaged, wherein a first spring is arranged and is configured to be compressed in the proximal position of the drill head, for pressing the drill head in the direction of the distal position; and a ring nest is formed inside the perforator; and a security spring is arranged within the ring nest, which is configured to be compressed in the distal position of the drill head, for pressing the drill head in the direction of the proximal position; characterized in that the first spring is arranged between the proximal end the drill head and the distal end of the drive shaft; and the ring nest) is formed inside the perforator between an external wall and a proximal external circumferential flange of the drill head and an internal wall and a distal internal circumferential flange of the chipping head. - a drive shaft with rotation axis (t), - a drill head with the same rotation axis (t), - a chipping head arranged coaxially around the drill head, a first connecting profile is provided on a proximal end of the drill head, and a second connecting profile is provided on a distal end of the drive shaft and the drill head is arranged so as to be displaceable with respect to the chipping head along the rotation axis (t) between a proximal position and a distal position, and in the proximal position the second connecting profile on the distal end of the drive shaft cooperates with the first connecting profile such as to transmit rotational motion from the drive shaft to the drill head, and in the distal position the first connecting profile on the proximal end of the drill head and the second connecting profile on the distal end of the drive shaft are disengaged, wherein a first spring is arranged and is configured to be compressed in the proximal position of the drill head, for pressing the drill head in the direction of the distal position; and a ring nest is formed inside the perforator; and a security spring is arranged within the ring nest, which is configured to be compressed in the distal position of the drill head, for pressing the drill head in the direction of the proximal position; characterized in that the first spring is arranged between the proximal end the drill head and the distal end of the drive shaft; and the ring nest) is formed inside the perforator between an external wall and a proximal external circumferential flange of the drill head and an internal wall and a distal internal circumferential flange of the chipping head.