Dental articulator having dual balls

A dental articulator capable of finely adjusting a three-dimensional articulation posture and exerting a secure fastening force by a lever is provided. The dental articulator includes a lower grip plate, a column, an arm, and an upper grip plate, wherein a first ball and a second ball are disposed between the arm and the upper grip plate, and wherein the dental articulator further comprises: a first clamp block having spherical recesses contacting with the first and second balls; a second clamp block having spherical recesses contacting with the first and second balls; a lever disposed on an outer surface of the second clamp block; an engaging bolt passing through the lever and the second clamp block into the first clamp block; and fastening bolts engaged into the lever to shorten a distance between the first and second clamp blocks.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2005-0020800, filed on Mar. 12, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dental articulator, and more particularly, to a dental articulator capable of accurately adjusting a three-dimensional articulation posture.

2. Description of the Related Art

In general, a dental articulator is a tool for producing artificial teeth, or dentures. An orthodontist mounts teeth molds made by a dentist on the dental articulator to produce the artificial teeth.

One type of conventional dental articulators comprises a base, a column erected at one end of the base, and arm rotatably disposed at one end of the column. Plaster molds are mounted on the base and attached to the arm. After the plaster molds are solidified, the plaster molds are hit and detached from the dental articulator. Due to hitting, the plaster molds may be damaged or broken. In addition, wastes of the plaster molds may contaminate environments. In addition, it takes too much time to solidify the plaster molds.

Another type of conventional dental articulators further comprises fastening means including upper and lower grippers for gripping upper and lower mouth molds on the arm and base. The upper and lower grippers are controlled with respective fastening bolts. In the conventional dental articulator, the grippers are fastened with engagement means. Therefore, after the articulation processes are performed several times, an engagement force is weaken, so that there may occur imperfect articulation due to change in an articulation posture of the dental articulator.

SUMMARY OF THE INVENTION

The present invention provides a dental articulator capable of finely adjusting a three-dimensional articulation posture and exerting a secure fastening force by means of a lever.

According to an aspect of the present invention, there is provided a dental articulator comprising: a lower grip plate on which a lower mouth mold is mounted; a column disposed at one end of the lower grip plate; an arm having one end rotatably disposed at upper end of the column; and an upper grip plate disposed at the other end of the arm, wherein a first ball having a shape of sphere is disposed at the other end of the arm, and a second ball having a shape of sphere is disposed at a neck portion erected at a center of the upper grip plate, and wherein the dental articulator further comprises: a first clamp block having spherical recesses spherically contacting with the first and second balls, wherein a screw hole is provided at a central portion of the first clamp block; a second clamp block having spherical recesses spherically contacting with the first and second balls, wherein an engaging bolt hole is provided at a central portion of the second clamp block; and an engaging bolt passing through the engaging bolt hole of the second clamp block to be engaged into the screw hole of the first clamp block.

In the aspect of the present invention, the dental articulator may further comprise: a lever disposed on an outer surface of the second clamp block, wherein screw holes are provided to both ends of the lever, wherein an engaging bolt hole is provided to a central portion of the lever; and fastening bolts engaged into the screw holes of the lever to shorten a distance between the first and second clamp blocks based on the engagement position.

In the aspect of the present invention, the lever may be inserted into a groove formed on the outer surface of the second clamp block to prevent the lever from rotating.

In addition, the engaging bolt may be located at a central portion between the first and second balls, and central axes of the fastening bolts may be located close to the central lines of the respective first and second balls.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view showing a dental articulator10according to the present invention.FIG. 2is an enlarged view showing a principal portion of the dental articulator ofFIG. 1.FIG. 3is a plan view showing the dental articulator ofFIG. 1.FIG. 4is a perspective exploded view showing a principal portion of the dental articulator ofFIG. 2.FIG. 5is a cross sectional view taken along a line A—A ofFIG. 3.

As shown inFIGS. 1 to 3, the dental articulator10according to the present invention includes a lower grip plate12on which a lower mouth mold T1is mounted, a column14disposed at one end of the lower grip plate12, an arm16having one end rotatably disposed at the column14, and an upper grip plate18disposed at the other end of the arm16. An upper mouth mold T2is mounted on the upper grip plate18. In addition, the one end of the arm16may be detachable from the column14.

In addition, grippers1and2for gripping the mouth mold T1, one of which is movable in opposite direction, are disposed on the lower grip plate12. Further, grippers3and4for gripping the mouth mold T2, one of which is movable in opposite direction, are disposed on the upper grip plate18. Since structures and operations of the grippers1,2,3, and4are well known to the ordinarily skilled, description on the gripper1,2,3, and4will be omitted.

According to the present invention, a first ball20having a shape of sphere is disposed at the other end of the arm16. In addition, a second ball24having a shape of sphere is disposed at a neck portion22. The neck portion22is erected at a center of the upper grip plate18. In the embodiment, the first and second balls20and24may have the same size.

First and second clamp blocks30and40are provided to spherically contact with the first and second balls20and24.

More specifically, referring toFIGS. 4 and 5, spherical recesses31and32are provided in an inner surface of the first clamp block30to contact with the first and second balls20and24. In addition, a screw hole33is provided at a central portion of the first clamp block30.

On the other hand, referring toFIGS. 4 and 5, spherical recesses41and42are provided in an inner surface of the second clamp block40to contact with the first and second balls20and24. In addition, an engaging bolt hole43is provided at a central portion of the second clamp block40.

A distance between centers O1and O2of the spherical recesses31and32of the first clamp block30is equal to a distance between centers O1and O2of the spherical recesses41and42of the second clamp block40. Therefore, the screw hole33and engaging bolt hole43are disposed along a straight line.

A lever50is disposed on an outer surface of the second clamp block40. Screw holes51an52are provided to both ends of the lever50, and an engaging bolt hole53is provided to a central portion of the lever50.

Preferably, in order to prevent the lever50from rotating, the lever50is inserted into a groove40aformed on the outer surface of the second clamp block40. More specifically, the lever50has a shape of an approximately rectangle, so that the lever50inserted into the groove cannot move. Therefore, when an engaging bolt60described later is preliminarily engaged, the lever50cannot move.

The engaging bolt60passes through the engaging bolt hole53of the lever50and the engaging bolt hole43of the second clamp block40to be engaged into the screw hole33of the first clamp block30.

The engaging bolt60preliminarily engages the first and second clamp blocks30and40between which the first and second balls20and24are interposed.

Fastening bolts70and70′ are engaged into the screw holes51and52of the lever50. By fastening the fastening bolts70and70′, the distance W between the first and second clamp blocks30and40is shortened to fasten the first and second balls20and24.

In the figures, reference numerals6and7indicate a pusher and a compression spring, respectively. When the pusher6is pushed, the compression spring7and the pusher6exert a force on the arm16, so that the arm16can rotate in a predetermined direction.

Now, operations of the dental articulator according to the present invention will be described.

(Preliminary Engagement of Clamp Blocks)

Firstly, as shown inFIG. 4, the first ball20connected to the arm16is brought close to the second ball24disposed on the upper grip plate18. Next, the first and second clamp blocks30and40are preliminarily engaged with the engaging bolt60. As a result, the spherical recesses31and32of the first clamp block30and the spherical recesses41and42of the second clamp block40spherically contact with the first and second balls20and24.

The preliminary engagement is a weak engagement of the engaging bolt60. Therefore, the upper grip plate10can freely change its three-dimensional posture with reference to the center O1of the first ball20or the center O2of the second ball24.

More specifically, the upper grip plate10can freely change its three-dimensional posture due to a spherical sliding contact of the first and second balls20and24with the spherical recesses31,32and41,42. In addition, due to the distance H between the first and second balls20and24, a height of the upper grip plate10can change.

The upper grip plate18can rotate about the three axes (X, Y, and Z axes) with respect to each of the centers O1and O2of the first and second balls20and24. The upper grip plate18can have any movements: horizontal rotation; left and right tilts; foreword and backward movements; leftward and rightward movement; and upward and downward movements. The upwards and downward movements means a change in the height of the upper grip plate18. Since the upper grip plate10can freely change its three-dimensional posture, it is possible to accurately articulate the upper and lower mouth molds T1and T2.

After the posture of the upper grip plate18is set up by using the engaging bolt60, a fastening force is exerted by using the fastening bolts70and70′ engaged in to the screw holes51and52of the lever50.

Namely, if the fastening bolts70and70′ are screwed, the first clamp block30is pulled by means of the lever50, and the second clamp block40is pushed. Therefore, the first and second clamp blocks30and40pull each other, so that a strong fastening force is exerted between the first and second clamp blocks30and40and the first and second balls20and24.

The lever50is fastened to the first clamp block30through the engaging bolt60by the fastening force. The associated moment is exerted between the fastening bolt70and the engaging bolt60separated from each other by a distance L.

The upper grip plate18is securely fastened by using the lever, so that it is possible to increase the fastening force in comparison to a conventional fastening mechanism using such a plaster material.

In addition, since the posture of the upper grip plate18is accurately set up by using a spherical contact during the preliminary engagement of the engaging bolt60, it is possible to accurately articulate the upper and lower mouth molds.

According to the present invention, a dental articulator has dual balls ratable around two axes, and the posture of the dental articulator can be three-dimensionally set up, so that it is possible to accurately articulate an upper grip plate. In addition, is possible to improve reliability of articulation by using a strong fastening force by means of a lever.