ASI Dental Specialties
3 – HANDPIECE CONTROL & OPERATION
www.asisupport.com
Page 1
65-0049 Rev-A, (11/12/20)
HANDPIECE CONTROL AND OPERATION
The system utilizes common dental industry type technology for selection and activation of air-driven drills and
instruments via a multi-position control block. The block contains individual gasket diaphragms that are held in
the closed position by compressed air supplied by the handpiece holders. When a dental handpiece is removed
from its holder, the compressed air is relieved off the gasket diaphragms for that particular instrument thereby
allowing compressed air and water to flow to the handpiece when the foot control is depressed. The flow rate of
this compressed air is controlled by individual stems on the top of the block and the flow of water by individual
needle valves with knobs located on the front and side of the unit.
Electric instruments, such as the ultrasonic handpiece and electric motor, are controlled via the same control
block. However, the compressed air that flows from the block is routed to an air/electric switch that uses an air-
driven piston to close contacts when activated to thereby send an electric signal for the ultrasonic and electric
motor to operate. When the foot control is released, these instruments will then turn off.
The system uses an air-driven poppet style foot-control valve that when depressed, will send compressed air to
the control block to operate whichever handpiece is removed from its holder. The foot control also features a
toggle valve for selecting water to spray from the handpieces. When the toggle is activated and the foot control
is depressed, it will allow an air signal to travel through the foot-control tubing to open a water relay valve
allowing water to flow to the selected handpiece. When the foot control is released, it will exhaust off the air to
the water relay valve and allow it to shut.
