Abstract: A dental handpiece has two sleeves rotatable relative to each other about a longitudinal axis. A chuck for a burr is driven by a gas turbine mounted in one of the sleeves. Air to drive the turbine is conducted through both sleeves by passages having a joint swivelling about the axis. Similarly, light, cleansing air and water are carried to the turbine vicinity and through swivel connections so that relative rotation of the handpiece sleeves can always be accomplished without interrupting any of the flows between the two sleeves.

Abstract: A dental turbine spindle assembly has a housing in which a pair of bearing supports are disposed concentric with an axis. A pair of bearings are disposed on the supports. A hollow spindle concentric with the axis is carried in a portion of the bearings and at one end projects through an opening in the housing. The projecting portion of the spindle is conical, is split and is threaded. A nut on the projecting portion is conical and is threaded to engage the spindle and has a circular portion partly disposed within a portion of a bearing. There is a wrench-receiving contour at the other end of the spindle accessible through an aperture in the housing.

Abstract: The usual dental handpiece has a shank with an end housing with openings therein at opposite ends of an axis. One opening reveals a non-circular spindle. The other opening, adjacent the other end of the spindle, receives a non-circular burr threadedly engaging the spindle. The wrench has a central frame adapted to extend around the housing with one end overlying one of the openings and with a second end overlying the other of the openings. One wrench end has an open-sided, non-circular slot adapted nonrotatably to engage the non-circular burr by a motion in a direction normal to the axis. The other wrench frame end has a shaft rotatable and slidable in a coaxial journal. The shaft is nonrotatably engageable with the non-circular spindle. A knob on the shaft is used in manually rotating and axially sliding the shaft within the journal. A spring urges the shaft toward one extreme position. The frame has frame stops engageable with the handpiece shank in extreme rotated positions.

Abstract: A dental handpiece has a housing with a removable cap together defining a chamber in which are coaxially mounted two bearings, each with an inner race and an outer race spaced apart to leave an intervening gap. Annular housing shields extend into the gaps. The bearings are mounted in elastomeric rings, each having a circular-cylindrical mounting surface. A shaft is disposed in the inner races of the rings. Between the bearings the shaft carries a turbine runner including two cups each having a hub and having peripheral turbine blades spaced apart a predetermined distance. The cups are mounted on the shaft with the cups facing each other so that the hubs and peripheries abut in a common plane normal to the axis and also defining a central annular space. The turbine blades are staggered with respect to each other. They receive air from an inlet passage in the housing and release air to an outlet passage in the housing.