JPH0411695Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present application relates to a root canal treatment instrument used for root canal treatment such as root canal enlargement of a tooth.

Conventional technology and its problems Conventionally, a cylindrical sliding chamber is provided in the head of a handpiece, and an operating piece consisting of a shaft is fitted into this sliding chamber so as to be able to move up and down as well as rotate. A sliding recess is provided in a part of the surface, which is limited by the left and right side walls into which an eccentric shaft that moves in a circular motion perpendicular to the sliding chamber due to the rotation of the rotating shaft is fitted. A root canal treatment instrument that performs treatment by vertically moving and alternatingly rotating an actuating piece through the actuating piece and imparting this movement to a hanging root canal cutting tool supported by the lower end of the actuating piece is known, for example, as disclosed in Japanese Patent Application Laid-open No. It is publicly known from 61-29347 and the like.

By the way, in the conventional root canal treatment instrument described above, the operating piece rotates alternately due to the force applied in the left and right direction when the eccentric shaft comes into sliding contact with the upper and lower surfaces of the sliding recess of the operating piece. Due to fluctuations in the load applied to the cutting tool during root canal treatment, the contact position of the eccentric shaft with respect to the upper and lower surfaces of the sliding recess changes over time.
Therefore, the reversal position of the alternating rotation may deviate greatly in the left and right direction from the center of the sliding recess, and the eccentric shaft may come into contact with the left and right side walls of the sliding recess.In this case, if a large load is applied to the cutting tool, the eccentric When the shaft is in contact with the left and right side walls, its rotation is restrained, and when the eccentric shaft is in contact with the left and right side walls, its rotation is restrained, preventing the rotation of the rotary shaft, which applies torsional force to the cutting tool and cuts the root canal. There is a risk of internal damage.
In this case, there was an operational inconvenience in that the load had to be removed by pulling the cutting tool out of the root canal.

Purpose and Structure The present invention solves the above-described disadvantages of the conventional sliding groove by removing the side wall of the sliding groove in which the eccentric shaft of the actuating piece engages and forming an annular groove around the entire circumference.

Examples and their effects Embodiments of the present application will be described in detail below with reference to the drawings.

Reference numeral 1 indicates a gripping portion of the root canal treatment instrument of the present application, and a rotating shaft a connected to the output shaft of a drive motor is inserted into the gripping portion 1. Reference numeral 2 denotes a head housing provided at the tip of the gripping portion 1, which includes a bottomed cylindrical main body 3;
It consists of a lid body 4 that closes the top surface, and these are connected by screwing. Reference numeral 5 designates a shaft-shaped actuating piece that fits inside the head housing 2 so as to be vertically movable and rotatable, and a fitting groove 6 is provided around the outer peripheral surface of the intermediate portion of the actuating piece 5. . Reference numeral 7 designates a cylindrical clamping member fitted into a through hole 8 formed in the axis of the actuating piece 5. The end portion of the cutting tool 10 for root canal treatment inserted into is removably fitted and held. Reference numeral 11 indicates a cam piece that is fixed to the tip of the rotating shaft a and applies an operating force to the actuating piece 5, and this cam piece 11 is connected to the rotating plate 12 that is fixed to the tip of the rotating shaft a, and It consists of an eccentric shaft 13 protruding from the front surface of the rotating plate 12 at an eccentric position with respect to the rotation center of the rotating shaft a, and the front part of the eccentric shaft 13 intervenes in the fitting groove 6.

In use, the rotating shaft a is rotated by a drive motor. Then, the eccentric shaft 13 moves circularly in the vertical direction and presses the sliding groove 6 in the vertical direction while slidingly contacting the upper and lower surfaces thereof. That is, eccentric shaft 1
The operating piece is moved up and down by the vertical motion component of the circular motion in step 3, and the eccentric shaft 13 and the upper surface 6a of the fitting groove 6 are
The actuating shaft 5 is given an alternating movement in the left-right direction by the frictional force in the left-right direction generated by the sliding contact between the lower surface 6b and the lower surface 6b. Therefore, the actuating piece 5 moves up and down and also performs an alternating rotational movement in the left and right directions, and this movement is caused by the cutting tool 1 for root canal treatment held between the holding members 7.
0, and cutting of the root canal, etc. is performed. When a large load is applied to the fitting groove 6 and the rotation of the operating piece 5 is restricted, the rotation of the eccentric shaft 13 is caused by slippage between the eccentric shaft 13 and the upper surface 6a to the lower surface 6b of the fitting groove 6. is not restrained, so the operating axis 5
The alternating rotation of is further maintained.

Effects of the invention As described above, according to the present application, since the engaging groove for engaging the eccentric shaft is provided along the outer periphery of the actuating piece, even when a large load is applied to the cutting tool, the rotating shaft remains stable. It has the advantage that the operation of the actuating piece can be maintained without restricting the rotational force, and there is no risk of damaging the inside of the root canal, allowing smooth root canal treatment work.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal cross-sectional view of the head, and FIG. 2 is a cross-sectional view of the head. In the figure, 1 is a grip part, 2 is a head housing, 5 is an operating piece, 6 is a fitting groove, 13 is an eccentric shaft, and a is a rotating shaft.

Claims (1)

[Scope of utility model registration request] A head housing in which a rotating shaft having an eccentric shaft protruding from its tip is inserted into a cylindrical gripping portion, and an operating piece consisting of a shaft body is fitted into the tip of the gripping portion so as to be vertically movable and rotatable. A root canal treatment instrument comprising: a body; and a fitting recess into which the eccentric shaft is fitted along the outer peripheral surface of the operating piece.