Nakanishi Inc.

Takao Kimura

Masanori Mizunuma

Keita Yokochi

The dental handpiece of a center-injection type has a bur sleeve () having an axial through hole capable of receiving and detachably holding therein a cutting bur having an axial through hole, upper and lower bearings () for rotatably supporting the bur sleeve (), and an injection nozzle () capable of being inserted into the axial through hole of the cutting bur from its proximal end for injecting cooling water through the other end. The dental handpiece () further has an upper seal means () arranged to seal the space between the upper region of the bur sleeve () and the upper bearing (), and a lower seal means (arranged to seal the space between the lower region of the bur sleeve () and the lower bearing ().

Dental handpiece of center-injection type

A dental handpiece has a head section, a neck section, a grip section connected to the grip section, and a drive unit connected to the grip section. The handpiece also has a detent unit for preventing relative rotation between the neck and grip sections. The detent unit includes a detent pin arranged axially slidably in the grip section, a spring for biasing the pin proximally so that the distal end of the pin is arranged inside the grip section in a rest position, and a catch formed at the proximal end of the neck section for receiving the pin for engagement. When the drive unit is brought into connection to the grip section, the pin is pressed distally to project out of the grip section into engagement in the catch, to thereby prevent relative rotation between the neck section and the grip section.

Dental handpiece

A dental handpiece where the chip air line is selectively switched to the ON-state for using both water and chip air, and to the OFF-state for using only water. The dental handpiece has a switching valve between the circumferential chip air channel and the chip air line in the handpiece body for selectively allowing and preventing communication. Opening the valve switches the communication to the ON-state in which chip air is allowed to pass from the circumferential chip air channel into the chip air line. Closing the valve switches the communication to an OFF-state in which chip air is prevented from passing from the circumferential chip air channel into the chip air line.

Dental handpiece with switching valve for fluid lines

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.

Growing community of inventors

Kanuma, Japan

Takao Kimura