Nakanishi Dental Mfg. Co., Ltd.

Nakanishi Inc.

Nakanishi Dental Mgf. Co., Ltd.

Yuichi Shibata

Sosaku Kawata

Eiichi Nakanishi

Tetsuji Suzuki

Tadashi Baba

A dental handpiece is disclosed, which includes a tool holder for receiving and detachably holding a dental treatment tool therein, and a tubular compressor disposed around the tool holder. The tubular compressor has a flared inner surface along a portion of its length. The tool holder and the tubular compressor are relatively slidable with respect to each other between tool holding and releasing positions. The tool holder has a plurality of integral presser tongues. Each of the presser tongues is partially separate from the tool holder with a slit to have a free tip and a connecting root with a reduced thickness. The flared inner surface of the tubular compressor elastically urges the tongues into pressure contact with the dental treatment tool to securely hold the tool in position, when the tool holder and the tubular compressor are in the tool holding position.

Dental handpiece with tool holder

A dental handpiece contains a tool for dental treatment operation, tool holding members for detachably and rotatably holding the tool, tool detachment members for abutting against the tool holding members to detach the tool from the tool holding members, and rotatable contact members capable of being point-contacted with the tool holding members. The rotatable contact members when contacted with the tool holding members is rotatable with the tool holding members.

Dental handpiece having rotatable contact member

A chucking device for a dental handpiece includes a cutting tool, a collet having a plurality of slits to permit the cutting tool to be received and attached in position in the collet, a rotational sleeve for transmitting rotation to the collet, a locking member adapted to permit the diameter of the collet to be changed, and a coil spring thrusting the locking member along the inserting direction of the cutting tool. The outer periphery of the collet has a tapered surface adapted to be enlarged in diameter along the inserting direction of the cutting tool. The locking member is shifted along the tapered surface under the thrusting force of the coil spring to change the diameter of the collet to hold the cutting tool therein. When the locking member is pressed down against the coil spring, the locking member is then moved along the tapered surface in a direction opposite to the inserting direction of the cutting tool to release the cutting tool to permit the tool to be detached from the collet. If a tapered surface flared in the tool releasing direction is provided on the inner periphery of the collet, a tapered surface is formed on the outer periphery of the collet on insertion of the cutting tool to provide the similar function.

Chucking device for dental handpiece

A dental handpiece has a handle portion including a powerhead assembly integrally supported on a front end of the handle portion and a base cylindrical member located in a cylindrical hollow portion of the handle portion. The base cylindrical member has a first axial central passage for a fiberscope, a second side passage for supplying air under pressure, a third side passage for supplying water and a fourth passage for exhaust. A middle connector has a large diameter front hollow portion and a small diameter rear hollow portion having internal threads, three radial openings provided through the connector at equally spaced locations, passages corresponding to the passages in the base cylindrical member and a tubular plunger slidably mounted thereon. A driven ball and a driving ball are slidably located in each radial opening for engaging a circumferential slot around an external rear end portion of a hollow mount insert threadedly fitted into the rear end portion of the base cylindrical member. A rear connector has passages corresponding to those of the base cylindrical member and the middle connector. An electric lamp is located in the larger diameter front hollow portion of the middle connector and has a plurality of fluid pressure passages for removing heat from the electric lamp. The tubular plunger is slidably movable for radially displacing the driven and driving balls to disconnect or assemble the dental handpiece.

Growing community of inventors

Kanuma, Japan

Yuichi Shibata