Patent ID: 8109762

Claim:
Dental handpiece for carrying a drill ( 1 , 12 ) and driving it in relative movement in a penetration direction (I-I), comprising: a body ( 2 ) with a proximal body end ( 2 a ) and a distal body end ( 2 b ), a demountable head ( 3 ), connected to the distal body end ( 2 b ), and adapted to hold the drill ( 1 , 12 ), abutment means ( 4 ) fixed to the dental handpiece by fixing means ( 5 ) to limit the depth of penetration of the drill ( 1 , 12 ) into the body of a patient, wherein the abutment means ( 4 ) comprise: an abutment body ( 6 ) with a bearing surface ( 6 a ) adapted to bear against the body of the patient at the end of penetration of the drill ( 1 , 12 ) into the body of the patient, a connecting section ( 7 ), fastened to the abutment body ( 6 ) and extending in a direction (II-II) substantially perpendicular to the bearing surface ( 6 a ), a guide support ( 8 ) forming a projection on the dental handpiece, adapted to hold the connecting section ( 7 ), detachably fixed to the dental handpiece, wherein: the fixing means ( 5 ) comprise a female cavity ( 90 ) produced in the dental handpiece, the fixing means ( 5 ) comprise a male protuberance ( 100 ), fastened to the abutment means ( 4 ), conformed to penetrate and to be retained in the female cavity ( 90 ), the dental handpiece includes locking means ( 50 ) that selectively prevent separation of the male protuberance ( 100 ) and the female cavity ( 90 ) and are actuated by the simple movement of assembling the head ( 3 ) onto the body ( 2 ), wherein the head ( 3 ) is removably fixed to the distal end ( 2 b ) of the body ( 2 ) by axial engagement in the distal end ( 2 b ) of the body ( 2 ) along an engagement direction (III-III), the female cavity ( 90 ) is produced on the head ( 3 ), the female cavity having a length L 1 , oriented axially in the engagement direction (III-III), the female cavity being opened at a proximal end ( 9 a ), the locking means ( 50 ) comprise an abutment facet ( 51 ), disposed at the distal end ( 2 b ) of the body ( 2 ), which blocks the proximal end ( 9 a ) of the female cavity ( 90 ) when the head ( 3 ) has been assembled onto the body ( 2 ), the male protuberance ( 100 ) of the fixing means ( 5 ) extends over a length (L 2 ) equal to or slightly less than the length (L 1 ) of the female cavity ( 90 ).