Abstract: The invention relates to a valve arrangement for controlling the flow of pressurized air, water and/or other media to at least one hand-operated tool, preferably an instrument for dental work. The valve arrangement includes for each tool a valve for each medium. According to the invention, each valve comprises a first valve part and a second valve part, those valve parts being arranged for relative movement between an open and a closed psoition under the influence of actuating means and further comprises a flexible hose connected at respective ends to the two first and second valve parts. When the valve parts occupy their valve-closed position, the part of the hose located between the two valve parts is folded so as to exhibit a flow-inhibiting fold or kink, whereas when the valve parts occupy their valve-open positions the flow-inhibiting fold is no longer present in the hose.

Abstract: The invention relates to a carrier device for hand tools for use in dental work. The carrier device incorporates holders for the tools and a supply for supplying pressurized air, water and/or electrical power to the tools. In accordance with the invention a magazine is arranged to carry the tools, and is movable in a manner to enable a selected tool to be moved to a pick-up station. The supply according to the invention comprises a single, flexible supply conduit incorporating channels for pressurized air, water and/or electrical power, and the tools and the supply conduit are provided with couplings for connecting a selected tool to the supply conduit in the pick-up station.