JPH10211215A - Head part structure of hand piece for dentistry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent loosening or falling-off of inner covers at a head part of a hand piece for densistry. SOLUTION: A head part comprises a housing 8, a chuck mechanism 1 rotatably installed in the housing 8, a bearing 3 to rotatably fix the chuck mechanism 1 in the housing 8, and inner covers 5, 6 to support the bearing 3. The inner covers 5, 6 comprises two vertically coupled inner cover members 5, 6 having threads A to be threaded with an inner wall part of the housing 8, and these are dropped into couter recessed parts 5a, 6a to be integrated with each other through parts of threads B in the reverse direction to the threads A. Even when the inner cover 5 starts removal, it is applied to the inner cover 6, and when the inner cover 6 tends to coming-off, the reverse threads B are threaded to prohibit coming-off of the inner cover 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a head portion of a dental handpiece, and more particularly, to a screw connection portion between a housing and an inner lid member in a head portion of a dental handpiece. The present invention relates to a screw connection mechanism.

[0002]

2. Description of the Related Art In a dental handpiece, for example, an air turbine or a micro engine, a cutting bar is mounted on a chuck mechanism rotatably mounted in a housing at the tip of the handpiece, and the chuck mechanism is connected to an air or motor. And various dental treatments such as tooth cutting are performed by the cutting bar.

In the handpiece described above, a bearing for rotatably holding the chuck mechanism and an inner lid for supporting the bearing are provided in the housing, or the inner lid is connected to the housing by screw connection. It is designed to be screwed to the inner wall.

[0004]

As described above, conventionally,
In many cases, the housing of the head portion and the inner lid member are screwed together with a screw in the dental handpiece. However, during use, the screw is loosened and the inner lid member comes off. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to prevent a middle cover member of a dental handpiece from loosening or falling off during use. Was made for the purpose of
The present invention is not limited to only the head part of the dental handpiece, but is suitably applied to other screw connection parts as needed.

[0006]

According to the first aspect of the present invention, there is provided a housing, a chuck mechanism rotatably mounted in the housing, a bearing for rotatably fixing the chuck mechanism in the housing, and A dental handpiece head having an inner lid for supporting the bearing, the inner lid comprising two cascaded inner lid members having screw screws screwed to an inner peripheral portion of the housing;
These two inner lid members are integrated into a mating recess by being screwed together in a direction opposite to the screwing screw, into a concave portion of the other.

According to a second aspect of the present invention, in the first aspect of the present invention, the two inner lids are integrally connected without play by a spring that presses the two inner lids in opposite directions. Is what you do.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of a main portion for explaining an embodiment in which the present invention is applied to a head portion of a dental air turbine handpiece. In the drawing, reference numeral 1 denotes a chuck mechanism. Reference numeral 2 denotes a blade integrally attached to the chuck mechanism 1. Reference numeral 3 denotes a bearing. Reference numeral 4 denotes an O-ring. Reference numerals 5 and 6 denote bearing cover inner lids. These inner lids 5 and 6 are a main part of the present invention. (Conventionally, it can be considered that these inner lids 5 and 6 are integrated). 7 is a middle lid spring, 8 is a housing, 9 is an upper lid, 10 is a push lid, 11
Is a push lid spring. As is well known, when the push lid 9 is pressed against the spring 11, the chuck mechanism 1 opens,
When a cutting bar (not shown) is inserted into the chuck mechanism 1 and the pressing force of the push cover 10 is released at the stage of insertion, the push cover 10
Is pushed back by the spring 11, the chuck mechanism 1 is closed, and the cutting bar is clamped by the chuck mechanism 1.

Here, when air is blown to the blade 2,
The chuck mechanism 1 rotates, and as described above, the cutting bar mounted on the chuck mechanism 1 rotates to perform tooth cutting and the like. As described above, when the inner lid is screwed into the housing to form the bearing presser, the force such as the cutting vibration applied to the chuck mechanism (rotary body) 1 is applied to the inner race 3a, the ball 3b, and the outer of the bearing. It is transmitted to the race 3c, the O-ring 4, and the inner lid, and the screwing between the inner lid and the housing may be loosened, or the upper lid 9 may come off.

The present invention has been made in order to solve the above-described problems. In the present invention, as described above, the inner lid is composed of two inner lids 5, 6, which are: For example, in the figure, a portion indicated by A is a right-hand screw, and a portion indicated by B is a left-hand screw.
As shown in the drawing, they pass through the left threaded portion B and are mutually dropped into the concave portions 5a and 6a of the other party. Recesses 5a,
Since the length of the screw B portion dropped into 6a is made shorter by the length of these concave portions, the screw B portion is
a, 6a, there is play between the inner lids 5 and 6, and the springs 7
Are applied in the direction in which they repel each other, and the screws B are brought together, whereby the inner lids 5 and 6 are assembled integrally without play.

As described above, after the inner lids 5 and 6 are integrated, the inner lids 5 and 6 are screwed to the inner peripheral wall of the housing 10 with the screw portions A,
With the spring 11 interposed in the push lid 10, the upper lid 9 is screwed into the inner lid 6, and then a jig is inserted through a hole 10 a provided in the push lid 10, and the inner lids 5 and 6 are tightened. To complete the head assembly.

Since the present invention has the structure as described above, when the inner lid 5 is loosened, it hits the inner lid 6, so that the inner lid 5 does not come off. Further, when the inner lid 6 is loosened, the reverse screw in the portion B starts to be screwed and tries to rotate in the direction of tightening the inner lid 6, so that the stopper does not hit here and the inner lid 6 does not come off. . Further, since the inner lids 5 and 6 are repelled by the spring 7, the loosening prevention effect can be obtained.

[0013]

As is apparent from the above description, according to the present invention, the inner lid member at the head portion of the dental handpiece does not become loose, so that the lid member falls off the head portion. No worries.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram for explaining an example of a head portion of a dental handpiece according to the present invention.

[Explanation of symbols]

1 chuck mechanism, 2 blades, 3 bearings, 4 O
Ring, 5, 6 ... Middle lid, 7: Middle lid spring, 8: Housing, 9: Upper lid, 10: Push lid, 11: Push lid spring.

Claims (2)

[Claims] 1. A dental device having a housing, a chuck mechanism rotatably mounted in the housing, a bearing for rotatably fixing the chuck mechanism in the housing, and an inner lid for supporting the bearing. In the handpiece head, the inner lid includes two cascaded inner lid members having screw screws that are screwed into the inner peripheral portion of the housing, and the two inner lid members are different from the screw screws. A head part structure for a dental handpiece, wherein the head part structure is integrated by being mutually dropped into a concave portion of a partner through a screwing screw portion screwed in a reverse direction. 2. The dental handpiece according to claim 1, wherein the two inner lids are integrally connected without play by a spring that presses the two inner lids in opposite directions. Head structure.