JP3339796B2 - Dental straight handpiece - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental straight handpiece, and more particularly, to cutting powder or the like cut by a cutting tool of the handpiece reaches a bearing provided in the handpiece. The bearing is designed to have a longer life by making it harder.

[0002]

2. Description of the Related Art FIGS. 2 (A) and 2 (B) are a main part configuration diagram and a partially enlarged detailed view for explaining an example of a conventional straight dental handpiece, wherein 1 is an axial direction. Chuck shaft 2 having a plurality of slits 1a,
The cutting bar 3 pinched by the chuck shaft 3 presses the tip end of the chuck shaft provided with the slit 1a against the cutting bar 2 or separates the cutting bar 2 from the cutting bar 2 to move the cutting bar 2 to the chuck shaft. Or a rotating shaft (the rotating shaft 3 is rotated by a motor (not shown)) which can be inserted into and removed from the chuck shaft 1. When the cutting shaft 2 is held between the rotating shaft 3 and a spring, 4 chuck shaft 1
Is pushed in the direction of arrow A.
The cutting bar 2 is firmly held via the chuck shaft 1 so that the cutting bar 2 rotates integrally with the rotating shaft 3.

FIG. 2A shows a state in which the cutting bar 2 is chucked by the chuck shaft 1. In this chuck state, when the lever 5 is turned around the axis P, the cam 6 is turned. When the chuck shaft 1 is further rotated, the chuck shaft 1 is moved in the direction B against the spring 4,
Thereby, the engagement between the rotary shaft 3 and the chuck shaft 1 in the Q portion is released, and the cutting bar 2 can be freely inserted into and removed from the chuck shaft 1.

As described above, in the conventional dental straight handpiece, the lever 5 is rotated against the spring 4 and the cutting bar 2 is inserted into the chuck shaft 1 in this state. Is returned to the original predetermined position, so that the cutting bar 2 is attached to the handpiece.

Further, in FIG. 2A, bearings 9 and 10 rotatably support the rotating shaft 3 with respect to the handpiece body 8, and the bearing 10 provided on the tip side of the handpiece is As shown in FIG. 2 (B), which shows a portion II in FIG. 2 (A) in an enlarged manner, the inner race 10a comprises an inner race 10a which rotates integrally with the rotating shaft 3 and an outer race 10b which is fixed to the handpiece body 8. The bearing 10 has an inner race retainer 11, outer race retainers 12, 13 and the like at the tip end thereof, and furthermore, the inner race retainer 11 and the inner race 10a rotate integrally with the rotating shaft 3. Dust-proof rotating disk 14, outer race 10b and outer race holder 12
And a fixed dust-proof disc 16 disposed between the outer race 10b and the outer-race retainer 13, and the like. The powder and the like are prevented from reaching the bearing 10. Note that, in the enlarged detailed view of FIG. 2B, arrows indicate a path through which dust reaches the bearing 10.

[0006]

As described above, in a straight dental handpiece, for example, during processing of a denture or the like, it is necessary to prevent or delay the dust cut by a cutting tool from reaching the bearing 10. , Bearing 1
In order to prevent the dust from being damaged or to prolong the service life, as described above, the conventional dust-proof wall increases the radial passage so that the dust moves mainly in the radial direction. Thus, the effective path length cannot be made sufficiently long (the centrifugal force makes the passage C in the outer peripheral direction almost useless, and the previous passage D in the center direction is replaced by the next passage C Does not work so effectively because the suction force acts due to the centrifugal force in the outer peripheral direction of the surface), but it was not always satisfactory.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and mainly has an axial path along which dust passes to a bearing, thereby extending an effective path until dust reaches a bearing. In order to prevent the bearing from being damaged or to prolong the life of the bearing.

[0008]

SUMMARY OF THE INVENTION The present invention provides a straight type handpiece main body, a rotary shaft having a hollow end portion rotatably disposed in the main body via a bearing, and a rotary shaft having a hollow inside. A bearing provided on the distal end side of the handpiece and having a chuck shaft disposed on the distal end side of the handpiece, the inner being fixed to the rotating shaft to prevent the inner race of the bearing from moving in the axial direction. A race holding member, and an outer race holding member fixed to the handpiece body to prevent the outer race of the bearing from moving in the axial direction. It is characterized by having nested concentric irregularities mutually, so that the dust cut by the cutting tool hardly reaches the bearing, I, in which aimed to extend the life of the bearing.

[0009]

1 (A) and 1 (B) are views for explaining an embodiment of a dental straight handpiece according to the present invention, in which FIG. 1 (A) and FIG. 1 (B) are the same as those in the prior art shown in FIG. 2 are assigned the same reference numerals as in FIG. 2 and their detailed description is omitted. FIG. 1B is an enlarged view of a portion I in FIG. 1A, and the enlarged detailed view is a configuration diagram according to the present invention. In the figure, reference numeral 21 denotes an inner race retainer integrated with the rotating shaft 3. The inner race retainer 21 prevents the inner race 10a of the bearing 10 from moving in the axial direction. An outer race holder 22 integral with the handpiece body 8 prevents the bearing 10 from moving in the axial direction of the outer race 10b by the outer race holder 22.
In the case of the illustrated example, the inner race presser 21 has a concave 2 in the axial direction.
1a, a protrusion 21b, and the outer race presser 22 has
The inner race retainer 21 has recesses 22a and protrusions 22b that nest with the recesses and protrusions of the inner race retainer 21, and the dust cut by the cutting tool passes through the path indicated by the arrow to the bearing 1
Reach 0. As described above, in the present invention, the dust generated by the cutting tool mainly reaches the bearing by following the path provided in the axial direction of the handpiece. The effective path up to the ringing is long, and the bearing can be maintained effectively.

In FIG. 1, reference numeral 23 is further forward of the outer race retainer 22, integrated with the rotating shaft 3, and
The recess 22 provided on the tip side of the outer race presser 22
a ', a dustproof member having a concave 23a and a convex 23b which engage with the convex 22b'. In this way, by expanding the dust path in the axial direction of the handpiece, the bearing is more effectively prevented from dust. Thus, the life of the bearing can be extended.

[0011]

According to the present invention, a straight handpiece main body, a tip end rotatably disposed in the main body via a bearing, and a hollow rotary shaft are disposed in the rotary shaft. An inner race holding member fixed to a rotating shaft at a tip end side of the bearing with respect to a bearing provided at a tip end side of the handpiece and for preventing an axial movement of an inner race of the bearing. And an outer race pressing member fixed to the handpiece body to prevent the outer race of the bearing from moving in the axial direction. The inner race pressing member and the outer race pressing member are mutually Because of the nest type concavo-convex shape, the dust cut by the cutting tool is mainly formed in the axial direction of the handpiece (in addition to the return Will reach the bearings by tracing the having) path path, the powder dust reaches the bearing, takes a considerable long time, it is possible to protect the bearing from the cutting dust effectively.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram for explaining an embodiment of a dental straight handpiece according to the present invention, and a partially enlarged detailed view thereof.

FIG. 2 is a main part configuration diagram for explaining an example of a conventional straight dental handpiece, and a partially enlarged detailed view thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Chuck shaft, 2 ... Cutting tool, 3 ... Rotating shaft, 8 ... Handpiece main body, 10 ... Bearing, 21, 22 ... Bearing presser.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-50309 (JP, A) JP-A-7-275259 (JP, A) JP-A-5-42169 (JP, A) JP-A-10- 277058 (JP, A) Fully open Hei 4-88922 (JP, U) Fully open sho 59-68518 (JP, U) Fully open sho 60-182019 (JP, U) Fully open sho 60-116304 (JP, U) JP-A-59-183219 (JP, U) JP-A-59-68517 (JP, U) Registered utility model 3014379 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61C 1 / Ten

Claims (1)

(57) [Claims] 1. A straight type handpiece main body, a rotary shaft having a hollow tip end rotatably disposed in the main body via a bearing, and a chuck shaft disposed in the rotary shaft. An inner race holding member fixed to a rotating shaft at a tip end side of the bearing provided on the tip end side of the hand piece to prevent axial movement of an inner race of the bearing, and the hand piece; An outer race pressing member fixed to the main body to prevent the outer race of the bearing from moving in the axial direction, wherein the inner race pressing member and the outer race pressing member are nested in the axial direction so as to be nested with each other; Dental straight handpiece characterized by having irregularities in a shape.