| http://www.w3.org/ns/prov#value | - From U.S. Pat. No. 3,032,878 a handpiece of this kind is known for dental treatment, said handpiece at one end being connected with a tube or cable for supply of pressurized fluid and at its other end carrying a pneumatic drill to be controlled by a bell-shaped sleeve in operable connection with a valve for simultaneous control of a cooling medium such as water or air and of the rotatory speed of
|
