MOTOR HANDPIECE, IN PARTICULAR FOR MEDICAL PURPOSES, PREFERABLY FOR A MEDICAL OR DENTAL LAB

摘要

The sleeve-type hand-piece housing (111) contains a chuck (106) for tools inserted from the forward end, and which is opened and shut by an external actuating member (104a). The chuck is mounted on a driving spindle (107) working in front and rear ball- or roller-bearings (114). At the front of the front bearing is a sealing system with washer working between the inner and outer bearing races (114a, 114b). The washer is preceded by one or more seals (146b, 146c). At least the seal (136b) adjacent to the washer works against the inner and outer bearing races, being typically mounted between them. The front bearing can be wider than a conventional one. the washer can bear against shoulders (114b, 114d), being secured by a detachable locking shoulder (145), preferably against the shoulder on the outer race. At the inside edge of the washer there can be an annular gap between it and the further adjacent seals.