Dental handpiece

Claim 1

In a dental handpiece comprising a grip sleeve; a head part provided at a first end of said grip sleeve; a drive unit comprised of an air operated turbine provided in said head part for driving a dental tool; a connecting portion arranged at the second, opposite end of the grip sleeve for free rotation relative to the grip sleeve, and releasably connected to said second end to the grip sleeve, said connecting portion being connected at its opposite end to a supply tube for supplying operating media, such as compressed air and/or water, to the headpiece; first through-flow channels provided in said connecting portion for the conveyance of the media through the connecting portion, terminating respectively in outlet apertures and extending into annular channels, which are sealed one from each other and from which there proceed second media through-flow channels provided in the grip sleeve and communicating with said first channels for all rotational positions of the connecting portion relative to the grip sleeve; and an elongate photoconductive device extending generally longitudinally of the grip sleeve and leading out near said head part to provide illumination in the region of the dental tool such that the elongate photoconductive device extends at least partly within the grip sleeve and ends in the axis of rotation of the connecting portion at the tool-side end of the connecting piece; and a light dispensing element which extends within the connecting portion and is located, at its end at the grip sleeve, substantially on the axis of rotation of the connecting portion so that light can be transmitted along the photoconductive device for all rotational positions of the connecting portion relative to the grip sleeve, the improvement comprising: a. said first media through-flow channels in the area of their outlet apertures being radially directed and the sealing of the annular channels one from each other being by means of sealing annuli mounted in annular grooves of the connecting portion, situated on both sides of the outlet apertures; b. the releasing of the connecting portion from the grip sleeve being by socket-connection, the holding members of the socket-connection being by means of said sealing annuli; c. said sealing annuli also functioning as bearings which support and allow rotation of the connecting portion relative to the grip sleeve; d. the supply tube having a tube end which is releasably connected to the connecting portion; and e. the light dispensing element near the supply tube end of the connecting portion being provided with one or more connecting elements for releasable connection of the light dispensing element to the supply tube, said light dispensing element also including an electrically operated bulb, and a plug socket set into one end of said connecting portion to receive a plug element provided on said bulb, and a cap threaded to one end of the connecting portion to shield said bulb, and electrical lines for said bulb which extend from said plug socket at said one end of said connecting portion through said connecting portion, and said connecting elements being provided adjacent to an end of said connecting portion and connected to said electrical lines, and air supply and air exhaust ducts for said turbine being provided in the handpiece, and in which said air exhaust duct is used to accommodate said electrical lines, and wherein said connecting elements are designed as contact annuli, which are arranged parallel to each other and at a distance from each other on a turbine air outlet exhaust stack and are designed to be sealed in relation to the latter and can be brought into connection with corresponding connecting contacts provided on the end of said supply tube.