JPS6323066Y2 - - Google Patents

Description

[Detailed description of the invention] This invention has a head attached to the tip of the shank, a motor attached to the rear end of the shank, and a cutting or polishing tool attached to the tip of the head to cut or polish teeth, etc. The present invention relates to a polishing dental handpiece.

(Conventional structure and its problems) Conventionally, a head was attached to the tip of the shank, a motor was attached to the rear end of the shank, and a cutting or polishing tool was attached to the tip of the head to cut teeth, etc. Alternatively, in a dental handpiece for polishing, the head is attached to the tip of the shank by engaging an engaging claw protruding from the outer wall surface of the neck of the head into an engaging recess formed in the inner wall surface of the tip end of the shank. In order to facilitate the engagement of the engagement claw into the engagement recess, play is provided between the engagement claw and the engagement recess in a direction parallel to the center line, so that the head does not move during cutting work. This has the disadvantage that the cutting sensation is not transmitted reliably to the user's hands due to the free movement in the direction parallel to the center line, making it difficult to perform the cutting work. Furthermore, since the meshing state between the head gear and the shank gear, which rotate at high speed, constantly changes, uneven wear occurs on the rotating members, which shortens the life of the dental handpiece.

(Purpose of the invention) The purpose of the invention is to prevent the head attached to the tip of the shank from floating in a direction parallel to the center line.

(Structure of the Invention) In the present invention, a spring member is interposed between the head and the shank to press the head and the shank in opposite directions, thereby preventing the head from moving.

(Description of Embodiment) Figures 1 to 3 show the configuration of an embodiment of the present invention, in which 1 is a motor incorporating an electric motor (not shown), and 2 is an electric motor protruding from the front end surface of the motor 1. a cylindrical guide tube protruding from the distal end surface of the motor 1 so as to cover the rotation axis (not shown) of the motor 1; a button 3 held movably in the radial direction on the outer peripheral wall of the motor 1; is an engaging pawl held movably in the radial direction on the outer circumferential wall of the guide tube 2; the button 3 and the engaging pawl 4 are biased in the radial direction by a spring (not shown); The engaging claws 4 protrude from the outer peripheral wall surface of the guide cylinder 2, respectively, and when the button 3 is pushed into the motor 1, the engaging claws 4 are drawn into the guide cylinder 2. Reference numeral 5 indicates a water supply port opened on the outer peripheral wall of the guide tube 2, 6 indicates a compressed air supply port opened on the outer circumferential wall of the guide tube 2, and 7 indicates the guide tube 2 before and after the water supply port 5 and the compressed air supply port 6. 8 is a contra shank (hereinafter referred to as a shank) in which a drive shaft (not shown) is rotatably installed, and the O-ring is wrapped around the outer peripheral wall of the shank 8. When the cylinder 2 is inserted, the engaging claw 4 is engaged with an engaging recess formed in the inner peripheral wall surface of the rear end of the shank 8 in the circumferential direction, and the motor 1 is rotatably attached to the rear end of the shank 8. At the same time, the water supply port 5 and the compressed air supply port 6 are connected to the rear end of the spray pipe 9 attached to the shank 8. 10 is a cap nut fixed on the outer peripheral wall surface of the tip of the shank 8; 11 is the shank 8 and the cap nut 10;
A guide hole drilled parallel to the center line between 12
A pin is slidably inserted into the guide hole 11, and a protrusion is formed at the rear end of the pin 12 to prevent it from falling out of the guide hole 11. 13 is pin 1
The pin 12 is biased toward the distal end (to the left in the figure) by the tension of the spring 13 (see FIG. 2), which is interposed between the rear end of the pin 12 and the end surface of the shank 8 (see FIG. 2). The tip portion thereof protrudes from the tips of the shank 8 and the cap nut 10. 14 is shank 8
The engagement recess (see Fig. 3), 16, is formed in the inner circumferential wall surface of the ring 15 screwed onto the inner circumferential wall surface of the distal end of the ring 15.
A head case part 18 rotatably includes a rotating shaft (not shown) to which a cutting tool 17 for cutting or polishing is detachably attached, and this head case part 1
A driven shaft 20 (see FIG. 3) has a gear (not shown) at its tip that meshes with a gear around the rotational shaft of shank 8, and a gear 19 that meshes with a gear at the tip of the drive shaft of shank 8 at its rear end. A head 22 consisting of a head neck 21 and a head neck 21 in which a
is a hole (third hole) formed in the outer peripheral wall of the head neck 21
23 is an engaging member (see FIG. 3) that has an engaging claw 24 integrally protruding from the outer peripheral wall surface of the rear end, and this engaging member 23 is loosely fitted into the hole 22 so as to be movable in the radial direction. be done. Reference numeral 25 denotes an arcuate plate spring (see Fig. 3) interposed between the hole 22 and the engagement member 23. The plate spring 25 biases the engagement member 23 in the radial direction to engage it. A pair of claws 24 protrudes from the outer peripheral wall surface of the head neck portion 21. 26 is placed on the engagement member 23 and is movable in the radial direction.
The button 26 is held at the position 1, and the stop pin 2 inserted into the head neck 21 is inserted into the stop hole 27 of this button 26.
8 is penetrated (see Figure 3).

In this embodiment configured in this way, the end surface of the head neck 21 inserted into the tip of the shank 8 is
When the head neck 21 is pushed into the shank 8 against the tension of the spring 13 while making contact with the tips of the pins 12 protruding from the tips of the shank 8 and the cap nut 10, the engaging pawl 24 is pushed into the shank 8. The head 16 is fitted into the engagement recess 14 and attached to the tip of the shank 8. At this time, the head 16 is urged toward the tip (leftward in the figure) by the tension of the spring 13. The head 16 does not move in the centerline direction. When removing the head 16 from the tip of the shank 8, push the button 26 into the head neck 21 to release the engagement between the engagement claw 24 and the engagement recess 14. Since the head 16 is pushed out toward the tip (to the left in the figure) by the force, it is only necessary to remove the head 16 from the shank 8.

Note that the pin and spring may be provided at the neck of the head.

(Effects of the invention) As explained above, according to the invention, the head no longer moves in the direction parallel to the center line during cutting work, and the cutting sensation is reliably transmitted to the user's hands. This has the advantage of making cutting work easier.
Furthermore, since the meshing state between the head gear and the shank gear, which are rotating at high speed, is always constant, uneven wear does not occur on the rotating members, which has the advantage of extending the life of the dental handpiece. Furthermore, when the engagement between the engagement claw and the engagement recess is released, the head is pushed out of the shank by the tension of the spring, so the head is no longer pulled out from the shank without being buried, and the engagement claw is removed. It has the advantage of being hard to break.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a dental handpiece equipped with an embodiment of the present invention, Fig. 2 is a configuration diagram of an embodiment of the invention, and Fig. 3 is a configuration diagram of an engaging claw and a button. . 1... Motor, 8... Shank, 12... Pin, 13... Spring, 16... Head, 17... Cutting tool.

Claims (1)

[Claims for Utility Model Registration] Engagement claws protruding in the radial direction are provided at the distal end of an engagement member protruding in the thrust direction from the rear end of the head or the distal end of the shank. A dental handpiece in which the head is attached to the distal end of the shank by engaging with an engagement recess provided on the inner circumferential wall surface of the rear end of the head using a spring means, the dental handpiece being provided at the rear end of the head. A pin is attached to a guide hole or a guide hole provided at the tip of the shank so as to be movable in the thrust direction, and the pin is inserted between the pin and the bottom of the guide hole so that the pin can move in the direction of the tip of the shank or in the direction of the shank. A dental handpiece comprising: a spring that presses the shank and the head attached to the distal end of the shank in opposite directions by biasing the head toward the rear end of the head.