Drive for dental tool holder with rotary drive shaft in housing - which rotates in opposite direction to that of intermediate shaft of drive transmission

摘要

In addition to the drive shaft (18), the housing (10,11) contains a rotary intermediate shaft (22) rotated by the drive shaft. A rotor shaft (6) holds the dental tool (5) and is driven in the same sense as the intermediate shaft. The axis of the drive and intermediate shafts enclose an obtuse angle. The axes of the intermediate and rotor shafts are orthogonal. The drive and the intermediate shafts of the active transmission rotate in opposite directions, just as the intermediate and rotor shafts. Pref. the drive shaft is hollow and carries an optical fibre inside. ADVANTAGE - Reduced handpiece length and hand stress.