Abstract: 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.

Abstract: An object is to provide a control device of a dental handpiece that is able to prevent giving a shock to the operator having the dental handpiece and the patient of treatment subject and also that is able to reduce the load onto the motor and to suppress heat generation thereof. The rotational direction of a motor 20 of a dental handpiece is switched at every certain time. At this time, before the rotational direction of the motor 20 is switched through switching of a relay 17, voltage to be applied to the motor 20 is reduced. It is thereby prevented that a large current flows into the motor 20 when the relay 17 is switched, and also that a large rotation torque is applied to a cutting tool rotationally driven by the motor 20.

Abstract: The light-emitting device 1 has a translucent cover 10 having a cylindrical shape and a flat light-projecting surface 11 facing to the light-emitting part of an LED 20. The LED 20 is arranged in close proximity with the flat light-projecting surface 11 in the translucent cover 10 to achieve efficient introduction of light from the LED 20 into a light-receiving surface of optical fibers.

Abstract: A drive motor of a dental handpiece for driving a cutting tool of the handpiece is provided that is connected to the dental handpiece on its front end side and includes a cylindrical casing; a rotor unit, which is rotatably supported inside the casing and outputs a driving force; a stator unit provided around the rotor unit inside the casing; and an air path which causes cooling air supplied from the rear end side of the drive motor to pass through an airtight cooling room circumferentially extending between the stator unit and the casing, and to be discharged from the rear end side.

Abstract: A dental handpiece capable of withstanding a higher torque load includes a driving source which rotates a first rotating shaft 3 which is supported rotatably in a rear casing 2R, which transmits rotation to a second rotating shaft 9 which is supported rotatably in a front casing 2F. First and second bearings 12,14 are disposed at a predetermined interval in a jacket 8 fixed in the front casing 2F to rotatably support the second rotating shaft 9, and a third bearing 13 is disposed between the first and second bearings 12,14. The third bearing 13 reduces the whirling of the second rotating shaft 9, thereby preventing the wearing and chipping of the teeth of gears caused by a shift of meshing positions between a first gear 5 and a second gear 10 and a shift of meshing positions between a third gear 11 and a fourth gear 73.

Abstract: 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.

Abstract: A dental handpiece is disclosed which has a head housing, a gear shaft having a gear part with gear teeth and a shaft part extending from the gear part, and a dust control seal sealingly fit on the circumferential surface of the shaft part of the gear shaft. The dust control seal is an annular member, and has a seal body, a first lip projecting radially inwardly from the seal body, and a second lip projecting radially inwardly from the seal body above and spaced apart from the first lip, with a space defined between a contact area between the first lip and the shaft part, and a contact area between the second lip and the shaft part.

Abstract: A dental handpiece having a reciprocal rotation means for converting a rotary motion to a reciprocating rotating motion is disclosed. The reciprocal rotation means includes a rotary body having input- and output-side guide grooves, input- and output-side semispherical concave surface formed at the ends of input- and output-side shaft part, respectively, of a rotary shaft extending in a grip of the handpiece, and input- and output-side guide pin protruding from the input- and output-side semispherical concave surface, respectively for engagement in the input- and output-side guide grooves, respectively.

Abstract: The present invention relates to a motor control method for a dental handpiece provided with a motor that rotationally drives a cutting tool. The control method includes a step A of limiting the motor current to a first limit current I1 when the load torque applied to the cutting tool exceeds a preset limit torque value, and a step B of controlling the motor current to be equal to or lower than a second limit current, which is lower than the first limit current, when it is detected that the motor stops rotating.

Abstract: The medical handpiece of the present invention includes a cutting tool having a flexible shank and a cutting bur, a plastically deformable tubular casing for the cutting tool, a handpiece body detachably holding the cutting tool, bearing members disposed in the casing, an inner intervening member for receiving the shank, and an outer intervening member arranged around the inner intervening member. The inner and outer intervening members are composed of a plurality of segments, and each segment is arranged between or on distal or proximal side of the bearing members. Each segment of the outer intervening member is further composed of a plurality of sub-segments. Annular members having the outer diameter that is larger than that of the outer intervening member are arranged between the sub-segments of the outer intervening member. The present handpiece provides improved operationality since shaking is hardly generated even when the casing is flexed.

Abstract: A liquid tank capable of preventing a gas passage from being clogged and a dental device including this liquid tank are provided. A liquid tank having an accommodation space in which a liquid L to be supplied to outside is accommodated includes a tank body having a mouth part with an opening, a cap mounted on the mouth part to close the opening, a liquid passage through which the liquid L in the liquid tank flows toward outside, a gas passage having a gap between the mouth part and the cap and a path communicatively connecting to the gap and the accommodation space, a liquid flow valve provided on the liquid passage to allow or inhibit a flow of the liquid L to outside, and an aeration valve provided on the gas passage to compensate for a negative pressure occurring in the accommodation space.

Abstract: The present dental handpiece has a burr sleeve, a head section, an air supply passage for introducing compressed air into the head section for driving the burr sleeve, and an air discharge passage for discharging the compressed air. The air supply passage includes a through hole axially extending through the rear terminal part of the handpiece, and a tubular pressure regulating member and an air supply tube connected in series between the through hole and the head section. The pressure regulating member has an aperture for allowing communication with the air discharge passage, and an annular valve body arranged axially slidably for opening/closing the aperture. When the pressure of compressed air passing through the air supply passage exceeds a predetermined level, the valve body is slid to open the aperture to discharge the compressed air for regulating the pressure of the compressed air to be supplied to the burr sleeve.