Abstract: Two nozzles 37 in pair are provided along an inner circumferential surface 21a of a concavity 21, air is blown out in a space from a blowout hole 37a provided at a tip end portion of the nozzle from a side where the nozzle 37 is provided aiming at an opposite side along an inner circumferential surface of the space and a powder contained in the concavity 21 is caused to rise up in the space, whereby the condition of the powder mixed with the air within the space is improved.

Abstract: The medical handpiece of the present invention has a cutting tool having a flexible shank and a bur provided at the distal end of the cutting tool for cutting an affected area, a tubular sheath for receiving the cutting tool therein, and a handpiece body for detachably holding the proximal end of the cutting tool and transmitting driving force from a drive source to the cutting tool. The sheath and the cutting tool are made flexible for a particular range, with the sheath being plastically deformable and the shank of the cutting tool being elastically deformable. The medical handpiece is further provided with a plurality of bearings arranged in the sheath, first interposed members that are tubular and flexible and arranged proximal to, distal to, and between the bearings, and second interposed members that are tubular and flexible and arranged inside the first interposed members.

Abstract: A dental handpiece having a grip with a head in which a treatment tool may be detachably attached. A front casing portion of the grip is continuous to a rear casing portion at an obtuse angle. A first rotary shaft is rotatably supported in the rear casing portion. A cylindrical jacket extends from the head and is arranged in the front casing portion toward the first rotary shaft. A second rotary shaft is rotatably supported in the jacket, and is operatively connected to the treatment tool at one end and to the first rotary shaft at the other end via a gear. The rotary shafts transmit driving force to the head section to drive the treatment tool. The jacket is provided with an engagement groove on its circumferential surface. An engaging device disposed in the rear casing portion detachably engages the groove, thereby fixing the jacket in the front casing portion.

Abstract: Two nozzles 37 in pair are provided along an inner circumferential surface 21a of a concavity 21, air is blown out in a space from a blowout hole 37a provided at a tip end portion of the nozzle from a side where the nozzle 37 is provided aiming at an opposite side along an inner circumferential surface of the space and a powder contained in the concavity 21 is caused to rise up in the space, whereby the condition of the powder mixed with the air within the space is improved.