Dentistry – Apparatus – Having motor or means to transmit motion from motor to tool
Reexamination Certificate
1999-09-21
2001-11-13
Lucchesi, Nicholas D. (Department: 3732)
Dentistry
Apparatus
Having motor or means to transmit motion from motor to tool
C433S126000
Reexamination Certificate
active
06315560
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a high-speed miniature drill such as a dental drill having an improved cover design for accessing the turbine chamber, an improved air return port within the chamber and an overall exterior form which facilitates cleaning and sterilization of the dental drill handpiece.
BACKGROUND OF THE INVENTION
Most air-driven, high-speed dental handpieces provide a means of accessing the turbine assembly for maintenance purposes. The turbine assembly is located in a chamber formed in the head of the drill and includes chuck, bearings and impeller. The turbine assembly has a much shorter service life than the handpiece body and must be replaced periodically. Routine cleaning and lubrication may also necessitate accessing the turbine assembly periodically. Typically, a removable threaded insert is provided for the purpose of removing or servicing the turbine assembly. This threaded insert frequently incorporates a push button mechanism for disengaging the chuck and removing the cutting tool or burr. Removal of the threaded insert is generally facilitated by the use of a specially designed key or wrench which may be hexagonal or octagonal in shape and matches the exterior profile of the threaded inset. Other designs incorporate slots or flats in the threaded insert for receiving a corresponding key or wrench. Such prior art designs are exemplified, for example by reference to U.S. Pat. No. 5,334,013 issued on Aug. 12, 1994.
Air-driven, high-speed dental handpieces incorporate one or more air passages for supplying air to the turbine assembly and one or more exhaust passages for evacuating the return air from the turbine chamber. The effective area of the air exhaust passage is of great importance since a larger opening reduces the back pressure in the turbine chamber and increases the efficiency of the energy transfer by the air flow through the turbine and out through an exhaust passage produced in the chamber side wall. Air exhaust passages produced by conventional manufacturing processes such as drilling, produce holes with a circular cross-section which do not take full advantage of the available area within the handpiece head. Furthermore, the total available area for the air exhaust passage leading from the turbine chamber is limited by the fact that the handpiece head is generally designed to be as small as possible in order to improve accessibility and maneuverability within the confines of the patient's mouth. Certain handpiece designs incorporate multiple, circular air exhaust passages in order to increase the effective exhaust area.
SUMMARY OF THE INVENTION
It is a feature of the present invention to provide a high-speed dental drill which substantially overcomes the above-mentioned disadvantages of the prior art.
It is a further feature of the present invention to provide a high-speed dental drill having an improved insert for providing access to the turbine assembly and wherein the insert has a smooth conical tapered circumferential external sidewall for frictional engagement by a mating conical bore of a key for the removal and connection of the insert.
Another feature of the present invention is to provide a high-speed dental drill which has an exhaust port in the turbine assembly chamber which has a non-circular cross-section in which the aspect ratio of the exhaust port is not equal to one whereby to increase energy transfer to drive the turbine.
Another feature of the present invention is to provide a high-speed dental drill wherein the handpiece, the drill head and the insert are radially symmetric to facilitate cleaning and sterilization.
Another feature of the present invention is to provide a high-speed dental drill design which has no sharp corners, flats or slots on its exterior surfaces and wherein the manufacture of the drill is simplified.
According to the above features, from a broad aspect, the present invention provides a high-speed dental drill which comprises a handpiece having a drill head at an end thereof. The drill head has a turbine assembly supported in a turbine chamber inside the drill head. The turbine assembly has a chuck rotatably secured between bearings. An impeller is secured about the chuck and aligned with an air inlet port in a sidewall of a turbine chamber. An exhaust port is also provided in the sidewall. Conduit means are provided in the handpiece to direct air pressure to the air inlet port to drive the turbine and rotate the chuck. The chuck has a work bit engaging free end which is exteriorly accessible. An insert is removably secured to the drill head and provides access to the turbine chamber. The insert has a smooth conical tapered circumferential external sidewall for frictional engagement by a mating connecting bore of a key for the removal and connection of the insert.
According to a further broad aspect of the present invention there is provided a high-speed dental drill wherein the turbine is driven by air under pressure being fed to the turbine chamber to rotate the turbine and wherein the air is exhausted from the chamber through an exhaust port formed in a sidewall of a chamber and having a non-circular cross-section in which the aspect ratio of the exhaust port is not equal to one thereby increasing the energy transfer to drive the turbine.
According to a still further broad aspect of the present invention there is provided a high-speed dental drill and wherein the handpiece, the drill head and the insert are all radially symmetric to facilitate cleaning and sterilization as well as manufacturing.
REFERENCES:
patent: 5772436 (1998-06-01), Matsui et al.
patent: 5797743 (1998-08-01), Bialey
patent: 5902108 (1999-05-01), Nakayama et al.
patent: 5938441 (1999-08-01), Brenner
Krouglicof Nicholas
Lampron Sylvain
Maranzana Roland
Ecole de technologie supérieure
Houle Guy J.
Lucchesi Nicholas D.
Swabey Ogilvy Renault
LandOfFree
High-speed dental drill does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-speed dental drill, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-speed dental drill will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2598011