Dental Handpiece Connecting Portion Receiving Alternative Illumination Members

The present invention relates to a dental handpiece including a handle portion which at one end has a holder for a driven tool and which at the other end is rotatably connected to a connecting portion which provides connection to a supply hose for supply media. Light issuing in the region of the tool may be produced by an incandescent lamp arranged in a recess in the connecting portion.

In a handpiece of such type, the function of the connecting portion is to provide connection of a given kind of supply hose to a series of different handle portions. Supply hoses of different configurations each have associated therewith their own connection portions which are permanently connected to the supply hose.

In a known type of connecting portion (see DE-C-31 04 239) the incandescent lamp which serves to produce the light is disposed in the center of the end of the connecting portion which is directed towards the tool. That has the advantage that only an electric line and not an optical line has to be passed through the connecting portion. If, on the other hand, the supply hose provides light, then a connecting portion of a substantially different structure must be used for that purpose.

The object of the present invention is to provide a connecting portion which with minor modifications can be selectively used for supply hoses which provide either light or an electrical voltage for supplying an incandescent lamp.

To attain that object, in accordance with the invention it is provided that a recess for receiving the incandescent lamp is arranged at a hose end of the connecting portion and opens on such end.

A particularly simple structural configuration is provided if contact pins of the incandescent lamp pass through a closure plate, which is towards the hose, of the connecting portion.

The connecting of the connecting portion to the handle portion is particularly simple when the light issues in known manner centrally from the connecting portion. Therefore, with an eccentric arrangement of the incandescent lamp, it is desirable if there is provided a mirror arrangement which provides for parallel displacement of light coming from the incandescent lamp, so that it issues axially from the connecting portion.

If light instead of electrical voltage is provided by the supply hose, then for the purposes of conversion of the connecting portion according to the invention, it is sufficient to use a glass rod or bar instead of the incandescent lamp. Most parts of the connecting portion are therefore identical for both types of supply hoses.

Further details of the invention are described hereinafter with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a dental handpiece;

FIG. 2A is an end view of a connecting portion of the dental handpiece of FIG. 1 and equipped with an incandescent lamp;

FIG. 2B is a section taken along line 2B--2B of FIG. 2A;

FIG. 2C is a section taken along line 2C--2C of FIG. 2A;

FIGS. 3A-3C are views similar to FIGS. 2A-2C, respectively, but wherein the dental handpiece is not equipped with an incandescent lamp; and

FIG. 4 is a longitudinal section illustrating change between the arrangement of FIGS. 2A-2C and the arrangement of FIGS. 3A-3C.

The dental handpiece shown in FIG. 1 comprises a handle member or portion 1 with a holder 2 for a tool (not shown) which is drivable by way of an air turbine 10. A light conduit 11 passes through the handle portion 2. Light issuing from the conduit 11 is directed toward the region of the tool.

In order to be able to operate with different types of supply hoses, the handle portion 1 is to be connected in each case to a suitable connecting member or portion 3 which makes the connection to the respective supply hose (not shown). The connecting portion 3 is connected rotatably relative to the handle portion 1 by way of an easily releasable quick-action coupling 12.

In accordance with the invention, a recess 5, within which can be positioned an incandescent light bulb or lamp 4 for producing light which is passed to the light conduit 11, is disposed in an end of the connecting portion 3 which is remote from the handle portion 1. Recess 5 opens away from handle portion 1, i.e. toward the supply hose (not shown). Contact pins 6 of the incandescent lamp 4 pass through openings in a closure plate 7 of the connecting portion 3 and can therefore be inserted directly into an end part (not shown) of a supply hose. The same applies for connections 14, 15, 16 and 17 for the supply to or from the dental handpiece of drive air, return air, treatment air and water.

While the passage of air and water through the rotatable connection between the handle portion 1 and the connecting portion 3 is provided in conventional manner, the arrangement according to the invention of the incandescent lamp 4 at the end of the connecting portion 3 which is towards the hose is novel. In order to provide for a central egress of the light beam to the end of the light conduit 11, in spite of the eccentric arrangement of the incandescent lamp 4, provided adjoining the incandescent lamp 4 is a mirror arrangement 8 in the form of a prism which can be removed after loosening a screw 13.

As can be seen from FIGS. 3A-3B, the connecting portion 3 remains almost unchanged if the provision of an incandescent lamp 4 is superfluous due to the supply hose already delivering a light beam to the connecting portion 3. Instead of the incandescent lamp 4, in this case for example use is made of a glass bar or rod 9 or other passive light guide device which merely serves to transmit light supplied thereto to conduit 11 via arrangement 8. A portion 18 of light guide 9 extends through an opening in closure plate 7 for optical connection to light supplied from the supply hose. As can be seen from FIG. 4, the manufacturer, for producing the desired connecting portion 3, only needs to make a choice between a glass rod or bar 9 or an incandescent lamp 4, whereas the remainder of the connecting portion 3 remains unchanged.