Dental handpieces with supplied operating media

A dental treatment installation comprising at least one dental handpiece having an air-operated drive motor and at least one outlet for discharging operating media used for dental purposes, such as cooling and/or rinsing media;

• a spray handpiece having a spray outlet for discharging a spray composed of water, or water and air;
• a control arrangement for controlling the supply of operating media to the handpieces;
• and a storage device for the handpieces having storage-switching means which are arranged to place the handpieces on stand-by to receive operating media upon extraction of the handpieces from the storage device, in which:
• the control arrangement includes supply sleeves having first, second and third ducts for supplying to the handpieces respectively cooling or rinsing air, drive air for the motor of the dental handpiece, and water, and couplings for releasably coupling the supply sleeves to the handpieces;
• and an operator-controlled device for regulating the supply of operating media to the handpieces and including first switching means for controlling the supply of air to drive the motor of the dental handpiece and second switching means for controlling the supply of spray, composed of cooling or rinsing air, or cooling or rinsing water, to the dental handpiece, and in which:
• each coupling comprises a first coupling member connected to one of the handpieces and a second coupling member connected to a respective one of the supply sleeves, said supply sleeve being capable of supplying operating media, under the control of said operator-controlled device, to the dental handpiece or to the spray handpiece, as desired, whenever the handpiece is coupled-up to any one of the supply sleeves via a respective coupling;
• and
• said first coupling member connected to the spray handpiece includes (a) means for blocking said first duct of any supply sleeve to which it is coupled in order to prevent the supply of the cooling or rinsing air to the spray handpiece, (b) connecting means for connecting said second duct of any supply sleeve to which it is coupled in order to supply said drive air to the spray outlet of the spray handpiece, (c) means communicating with said third duct of any supply sleeve to which it is coupled in order to supply water to the spray outlet of the spray handpiece (d) an external operating means provided on the spray handpiece for preventing the supply of air to the spray outlet as and when required, said external operating means comprising an annular switching device which is axially displaceable on the exterior of the spray handpiece;
• and including a radially inwardly extending projection provided on the annular switching device, an opening formed in the spray handpiece through which said projection extends, and a blocking member constituting said connecting means and arranged in the spray handpiece to be engaged by said projection for movement between opened and closed positions relative to a passage for the flow of drive air through the spray handpiece.