Dentistry – Apparatus – Having motor or means to transmit motion from motor to tool
Patent
1984-01-12
1985-03-26
Peshock, Robert
Dentistry
Apparatus
Having motor or means to transmit motion from motor to tool
433131, A61C 108
Patent
active
045070857
DESCRIPTION:
BRIEF SUMMARY
This invention relates to dental instruments including a handpiece comprising a tool carrying head being removably mounted at the fore end of an intermediate section of the instrument, which contains a micromotor for driving the tool carried by the head of the handpiece, the rear end of the intermediate section being connected to a supply source by means of a flexible sheath and the handpiece being freely rotatable relative to said sheath, around the axis of the instrument.
With the instruments of this type which are known, it is the handpiece alone which is rotatable. The intermediate section containing the motor for its part is rigidly connected to a tip means secured to the end of the flexible sheath connecting the dental instrument to the supply source. To ensure the rotational motion of the handpiece, its rear end is provided with a bore fitted on a central sleeve of the intermediate section, which protrudes from its fore end and through which pass members connecting the rotor of the micromotor to the tool borne by the head of the handpiece. Since the micromotor rotates at relatively high speeds with modern dental instruments, it is important that the working place of the tool is cooled while blowing off the debris produced by that tool. For this purpose, the handpiece is provided either with a single nozzle arranged for spraying the working place with an air and water mixture, or with a pair of nozzles placed side by side to blow toward the working place of the tool, the one, water, and the other one air atomizing said water. These fluids are supplied by the supply source. They are fed to the instrument by tubes located in the flexible sheath and they pass through the intermediate section and the handpiece by means of conduits provided entirely or at least partially inside elements.
In order to connect a conduit of the intermediate section to a conduit of the rotatable handpiece, the first solution that suggests itself consists of a flexible tube extending on the outside of the instrument between an outlet of the intermediate section and an inlet of the handpiece. It is also the first one that has been introduced in practice. In this case the flexible tube usually forms part of the handpiece to which it is permanently connected and at its free end it carries a plug-in tip means which can be inserted in the intermediate section.
Because of the bulk of such a flexible tube, the handpiece comprises a single nozzle. An air and water mixer is provided upstream of said flexible tube possibly in the tip means of its free end, so that a single external tube suffices to produce the cleansing and cooling jet (CH-PS No. 604 670).
That known solution has, however, the drawback that the rotary motion of the handpiece is limited by the length of the outside tube. Moreover, the longer the tube, the greater the risk to be torn away upon geting caught on some foreign body member. It can also interfere with the handling of the instrument because it precisely extends in the area thereof which is held between the finger tips.
Therefore, solutions with air and water conduits entirely enclosed within the instrument parts are preferred today. The connection between a conduit of the intermediate section and the corresponding conduit of the rotatable handpiece is then ensured by an annular space provided between two adjoining surfaces of the intermediate section and of the handpiece, the hermeticity of that annular space being ensured by means of two packings arranged on both sides thereof, in grooves either of the intermediate section or of the handpiece. In practice, these grooves are formed in cylindrical surfaces and not in plane surfaces, in order that the packings do not drop out of their lodging when the handpiece is changed (GB-PS No. 1 519 513, DE-PS No. 2 334 448, CH-PS No. 604 670).
On attaching a handpiece to the intermediate section of the instrument, as is frequently done, said packings are thus either compressed to enter a bore or stretched to engage a cylindrical surface, depending on whether they are located
REFERENCES:
patent: 4020556 (1977-05-01), Sotman
patent: 4080737 (1978-03-01), Fleer
patent: 4182038 (1980-01-01), Fleer
Mosimann David
Schnider Jean-Pierre
Walther Theodor
Bien-Air
Peshock Robert
LandOfFree
Dental instrument with handpiece does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dental instrument with handpiece, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dental instrument with handpiece will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1292359