Dental drill cooling air supply - has bush for changeover from air supply from motor to separate air supply line

摘要

The dentist's drill has an air entry channel (3) through its handle (1) immediately ahead of the drive motor (10). Air can be supplied to cool the head of the tool through a supply line passing through a plug (9) in a hole (4) tapped through the side of the handle. This passes through a bush (5) which has a closure screw (8) at its rear and into the air channel (3). If the motor includes its own cooking air supply, the bush is rotated through 90 deg. when the plug (9) is removed. This blocks up the side entry (4) and air passes through a hole (2) underneath and into the bush from that side. Several variations of design based on this principle are shown.