Image Number 3 for United States Patent #5476380.
A dental handpiece includes an end grip member gripped by an operator during use. The end grip member has a first end to be connected to an air supply and a second end on which is selectively detachably mounted a tool holder supporting a tool that is driven either by a mechanical structure or by an air turbine, depending upon the particular tool holder mounted on the end grip member. Within the end grip member is an air motor, and a first air line extends from the first end to the air grip motor. When the tool holder includes the mechanical structure, then the first air line supplies air to the air motor, thereby to transmit power to the mechanical structure. A second air line extends through the end grip member between the first and second ends thereof. When the particular tool holder mounted on the end grip member includes an air turbine, the second air line supplies air thereto. An adjusting mechanism is mounted on the end grip member to selectively open one of the first and second air lines while closing the other of the second and first air lines.