Dentistry – Apparatus – Having motor or means to transmit motion from motor to tool
Reexamination Certificate
1999-05-20
2001-05-08
Lewis, Ralph A. (Department: 3732)
Dentistry
Apparatus
Having motor or means to transmit motion from motor to tool
C433S127000
Reexamination Certificate
active
06227854
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a releasable chucking device for a rotating medical or dental tool.
2. Description of the Related Art
A special type of medical or dental tools, which are operated with relatively high torques, have at the chucking end in the tool shaft a flattened portion for transmitting the torque. In addition, the tools have in the area of the flattened portion an annular groove, wherein a holding member of the chucking device protrudes radially inwardly into the annular groove during the operation of the tool in order to hold the tool in axial direction.
The circular cylindrical tool shaft is received in a circular cylindrical recess of the handpiece head with as little play as possible. This play usually is a few hundredth of a millimeter in the radial direction; this is due to the tolerances of the dimensions particularly of the tool shafts.
However, in a chucking device of the above-described type, even this little play has drastic effects on the operation of such tools because of the extremely small dimensions of the tool and, thus, of the tool head. This is because a play of a few hundredth of a millimeter means that the drill is movable in an order of magnitude which may correspond to half the chucking height. Particularly in view of the rates of rotation used in such tools, this means that the dimensional accuracy of the bore is significantly impaired, the quality of the bore surface and the bore edges is significantly reduced and vibrations and pain for the patient are increased.
Tool holders for such tool shafts are known, for example, from DE 30 12 240 A, DE 34 42 386 A, DE-G 89 13 626.8 U, EP 0 322 896 B, EP 0 470 324 B, and EP 0 820 734 A. All these known tool holders have the disadvantages described above.
SUMMARY OF THE INVENTION
Therefore, it is the primary object of the present invention to provide a tool chucking device in which the above-described disadvantages do not occur and which still has all the advantages of the previously known tool holders.
In accordance with the present invention, this object is met by providing an additional frictionally engaging support of the tool, for example, by providing the sleeve surrounding the circular cylindrical portion of the tool shaft with a collet or to construct the sleeve as a collet.
As a result of the configuration according to the present invention, an additional frictionally engaging support of the tool shaft is achieved, wherein the support is free of play and the holding force is certainly sufficient for the fixed support during the usual operation, aside from the forces necessary for transmitting the drive torque, and produces during normal operation an essentially play-free support, which, in addition, centers the tool.
In accordance with a further development of the invention, the collet is released by actuating a push button, wherein this push button also releases the radial engagement in the area of the groove of the tool shaft.
The present invention also relates to a special configuration of this radially releasable engagement.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
REFERENCES:
patent: 2911721 (1959-11-01), Staunt
patent: 4398886 (1983-08-01), Schuss et al.
patent: 4661062 (1987-04-01), Seigneurin
patent: 5011408 (1991-04-01), Nakanishi
patent: 5037299 (1991-08-01), Nakanishi
patent: 5090906 (1992-02-01), Pernot
patent: 5591028 (1997-01-01), Fujiki et al.
patent: 5653453 (1997-08-01), Nakamoto
patent: 5730596 (1998-03-01), Rosenstatter
patent: 5836766 (1998-11-01), Gugel et al.
patent: 3012240 (1981-10-01), None
patent: 3442386 (1985-06-01), None
patent: 8913626 (1991-05-01), None
patent: 0470324 (1992-02-01), None
patent: 0322896 (1993-03-01), None
patent: 0820734 (1998-01-01), None
Helfenbein Gerald
Schatz Norbert
Dentalwerk Burmoos Gesellschaft m.b.H.
Kueffner Friedrich
Lewis Ralph A.
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