Abstract: The specification discloses a multiple dental handpiece control system in which lifting one handpiece out of its hanger blocks supply of power and coolants to all other handpieces. Each handpiece has an individual control unit and a blockout unit. When a handpiece is lifted from its hanger, it actuates a valve to cause a piston in its control unit to shift to a condition causing supply of power and coolant fluid to that handpiece and cutting off power to the corresponding pistons in the other control units thereby preventing supply of power and coolant fluids to the other handpiece.

Abstract: Dental suction apparatus is a modular construction, made up of a plurality of modules joined fluid-tight side-by side. A main suction duct extends through all of the modules. At least two of the modules have connection for suction hoses each having a suction nozzle, holders being provided on the modules for holding the suction nozzles when not in use. At least one module has a filter chamber connected between a suction tube and the main suction duct. A removable filter unit in the filter chamber has a basket-shaped filter on a stem by means of which the filter can be removed through on opening closed by a hinged cover. A cap on the stem provides a seal for the filter chamber. Flow of air from the suction tube of each suction tube module to the main suction duct is controlled by a valve in the form of a bellows provided with a telescopic guide and with a control valve for controlling the expansion and contraction of the bellows by differential pressure.

Abstract: The specification discloses a multiple dental handpiece control system in which lifting one handpiece out of its hanger blocks supply of power and coolants to all other handpieces. Each handpiece has an individual control unit and a blockout unit. When a handpiece is lifted from its hanger, it actuates a valve to cause a piston in its control unit to shift to a condition causing supply of power and coolant fluid to that handpiece and cutting off power to the corresponding pistons in the other control units thereby preventing supply of power and coolant fluids to the other handpiece.

Abstract: A dental treatment apparatus having a plurality of dental instruments releasably retained in an instrument-holding device. A control and display arrangement controls the operation of an instrument upon extraction from the holding device, and displays the magnitude of an operating parameter of the instrument on a display device. A control data store is arranged to store pre-determined fixed control data values for the operating parameters of the instruments. To enable the user to alter the predetermined fixed values, a forward-backward counter is connected to the data store which can also store the altered values. A data converter is connected to the counter and to the display device for converting the instantaneous value stored in the data store to a corresponding service datum instantaneous value to be displayed by the display device.