Oscillating dental angle handpiece

An oscillating dental angle handpiece for dental tools is described. The handpiece has a hollow housing body, that defines a first longitudinal cavity suitable for coaxially containing inside the first longitudinal cavity a driving shaft, and a second transversal cavity, arranged at an end of the first cavity and having an axis incident with the axis of the first cavity, as well as a driven holder, in which a rotary movement of the driving shaft is transformed into oscillating movement of the driven holder. Additionally, the handpiece is entirely made from synthetic material.

The present invention refers to a dental angle handpiece equipped with oscillating movement for dental tools. More specifically, the invention refers to an oscillating dental angle handpiece suitable for being used as a disposable angle handpiece.

There are known oscillating dental handpieces, in other words equipped with an oscillating movement, made from metallic material and therefore not disposable, but rather able to be sterilized before being used again.

These differ from rotary dental handpieces in which a rotary movement is transmitted to dental tools like for example a drill.

Oscillating dental handpieces, on the other hand, transmit an alternating back-and-forth linear oscillating movement to the tool. Non-limiting examples of such tools are files, strips and polishing tools. Such oscillating movement tools are particularly useful in interproximal prophylaxis, restorative or orthodontics treatments.

The purpose of the present invention is to make an oscillating dental angle handpiece that can be used as a disposable angle handpiece.

Another purpose of the present invention is to make an oscillating dental angle handpiece to which it is possible to fix different types of tools.

A further purpose of the present invention is to make an oscillating dental angle handpiece that allows the tools to be oriented.

Another purpose of the present invention is to make an oscillating dental angle handpiece that is particularly simple and functional, with low costs.

These purposes according to the present invention are accomplished by making an oscillating dental angle handpiece as outlined in claim1.

Further characteristics are provided in the dependent claims.

With reference to the figures, an oscillating dental angle handpiece equipped with oscillating movement for dental tools is shown wholly indicated with10and comprising a hollow housing body12, that defines a first longitudinal cavity12A suitable for containing inside it, in a coaxial manner, a driving shaft13and a second transversal cavity12B,112B, arranged at an end of the first cavity12A and having its axis incident with the axis of the first cavity12A, suitable for containing a driven holder20, schematically shown inFIG. 1, the different variant embodiments of which20′,20″,20′″ and120are shown for example inFIGS. 2-9.

The common parts of the angle handpiece10, described hereafter individually, can on each occasion have the specific components associated with them, which differ according to the various embodiments.

The driving shaft13is suitable for being set in rotation by an external micromotor, not shown. Preferably, the transfer of the rotary motion from the micromotor to the driving shaft13takes place through an adapter handle11, shown as an example only inFIG. 5, able to be connected to any of the angle handpieces10according to the invention. Alternatively, the angle handpiece10could also be directly connected to the micromotor.

The driving shaft13comprises a plurality of annular projections14, having a diameter slightly smaller than the diameter of the portion of the hollow housing body coupled with them, which keep the driving shaft13coaxial with the hollow body12during rotation. The annular projections14also constitute coupling elements for a locking cap16, which is positioned in a hole17of the hollow body12after the axial mounting of the driving shaft13in the hollow body12to keep the driving shaft13axially in position. For example, between two adjacent annular projections14there is an annular seat15for the engagement of the end of the locking cap16(FIGS. 2 and 3) or one of the annular projections14themselves is received between two projecting teeth of the locking cap16(FIG. 6).

The rotary movement of the driving shaft13is transformed into alternating back-and-forth linear oscillating movement of the tool through a cam connection between a cam18, made in the form of a cylinder arranged at the end of the driving shaft13in non-coaxial position, in other words offset with respect to the rotation axis of the driving shaft13, and the driven holder20, equipped with a suitable seat21,121, having width x slightly greater than the diameter of the cam18, measured in the direction parallel to the translation axis F of the linear oscillating movement. With the rotation of the driving shaft13, the cam18pulls the driven holder20with it, forcing it to carry out an oscillating back-and-forth movement along an axis F.

The driven holder20is driven in its oscillating movement by the walls of the second cavity12B,112B of the hollow housing body12, which in the example shown as an example and not for limiting purposes is arranged with a non-perpendicular angle with respect to the axis of the driving shaft13. In these examples, therefore, the oscillation axis is also arranged with a non-perpendicular angle with respect to the rotation axis of the driving shaft13.

The handpiece10according to the invention generates an alternating linear oscillating movement of the driven holder20that can have different lengths, for example comprised between 0.1 mm and 5 mm.

The driven holder20, according to the invention, is not subject to any rotary movement about the translation axis.

The driven holder20is schematically shown inFIG. 1, without the tool itself. The tool can be removably connectable to the driven holder (FIGS. 2, 3 and 5-9) or it can be made as an enbloc with it (FIG. 4).

The angle handpiece10is made entirely from synthetic material, for example polycarbonate, polyamide (such as Nylon), PEEK, possibly containing reinforcing fillers.

The angle handpiece made from synthetic material can optionally also be sterilizable, which is not strictly necessary for a disposable angle handpiece.

FIG. 2shows a section of an embodiment of the oscillating angle handpiece10, coinciding with what is shown and described for the angle handpiece10ofFIG. 1, equipped with a first embodiment of the driven holder20′ suitable for receiving the tool in a removable manner. The driven holder20′ is provided with a hole22, parallel to the direction of oscillation, suitable for receiving a shank30of a dental tool in removable engagement.

The shank30can be made as an enbloc with the tool, according to an example not shown, or, as shown inFIG. 2, it can be suitable for receiving, in removable engagement in a suitable seat31, a dental tool, non-limiting examples of which are shown in international application WO 2010095017 A1, which should be integrally referred to here. In the embodiment shown inFIG. 2, the engagement seat31for the dental tool is further provided with an elastic retaining tooth32for snap-locking with the fastening portion of the tool.

The removable shank30can be rotated inside its seat, consisting of the hole22, by 360° in order to orient the dental tool with respect to the most suitable position for the specific dental treatment, according to any desired angle, in other words according to continuous- positions. A retaining ring23(O-ring) ensures sufficient friction with respect to the rotation, so that the dental tool, in use, is not subject to rotation with respect to the handpiece10.

FIG. 3shows a section of an embodiment of the oscillating angle handpiece10, coinciding with what is shown and described for the angle handpiece10ofFIGS. 1 and 2, equipped with a second embodiment of the driven holder20″ also suitable for removably receiving the tool33. The driven holder20″ is made in two portions, a front portion20″A suitable for carrying the tool and a rear portion20″B coupled with the driving shaft13. The two portions are connected together through an articulation24so as to allow a mutual rotation substantially equal to 360° in order to orient the dental tool with respect to the most suitable position for the specific dental treatment, according to any desired angle, in other words according to continuous positions.

The retaining ring23, of the O-ring type, positioned near the articulation, ensures sufficient friction with respect to the rotation, so that the dental tool, in use, is not subject to rotation with respect to the handpiece10.

The front portion20″A, in the example shown inFIG. 3, comprises a piece of shank30′, made as an enbloc with such a front portion20″A and equipped with the seat31for the removal engagement with a dental tool, of the type described for the embodiment ofFIG. 2, in particular equipped with the elastic retaining tooth32for the snap-locking with the fastening portion of the tool.

According to a third embodiment of the oscillating handpiece10object of the invention, shown inFIG. 4, the driven holder20′″ comprises a front portion20′″A directly carrying a dental tool33made as an enbloc with the angle handpiece10, in other words not removable with respect to the driven holder20′″.

According to further variant embodiments of the oscillating angle handpiece according to the invention, not shown, the tool made as an enbloc with the driven holder could have a fixed orientation, in other words not be rotatable about the axis parallel to the direction of oscillation, or such a rotation could be carried out with other equivalent means to the articulation24to carry out a continuous or discrete adjustment of the position.

In the embodiments shown as examples and not for limiting purposes inFIGS. 1-4the driven holder20′,20″,20′″ and the second cavity12B of the hollow housing body12that receives it have a matching cylindrical shape.

According to a fourth preferred embodiment of the angle handpiece10object of the invention, the hollow housing body112B and the driven holder120have, along their shell, a matching conical shape, preferable in order to simplify the production by moulding of the pieces made from synthetic material, with the exception of a flat coupling portion parallel to the translation axis F. Indeed, the driven holder120has, on the outer shell, a flat portion25oriented according to the translation axis F of the linear oscillating movement and arranged on the diametrically opposite side with respect to the seat for the cam121. The second cavity112B of the hollow housing body12is consequently equipped with a matching plane19, projecting inside the cavity and also oriented according to the translation axis F of the linear oscillating movement.

The cam18, according to this embodiment, is received in a seat121, the height y of which measured in the direction perpendicular to the translation axis F is progressively shorter in the direction of the end with a larger diameter of the conical driven holder120, in other words at the end suitable for receiving the tool. Indeed, the seat121has a bottom wall that when the angle handpiece is mounted is parallel to the front wall of the cam18facing it.

This particular coupling between the cam18and the seat121is selected to act jointly with the coupling between the driven holder120and the cavity112B on a plane parallel to the direction of translation F to ensure that the movement of the tool is exclusively alternating linear oscillating. Indeed, during the rotation of the driving shaft13, the cam18keeps the driven holder120constantly in contact with the cavity112B along the flat coupling. However, the two characteristics could also have application separately.

In the angle handpiece10according to the fourth embodiment the hole22of the driven holder120, which receives the shank30, is made axially centred.

The shank30preferably provides a seat34for holding the O-Ring23and a slit35at the opposite end with respect to the engagement seat31of the tool for the fixed engagement, of the removable or non-removable type, with the projecting pin41of the safety cap40.

The safety cap40, which holds the shank30in the holder when the angle handpiece10is operating, is shown inFIGS. 5-9in the removable embodiment, but it could also be fixed, thus not allowing the removal of the shank30from the driven holder120.

In the removable version shown, the safety cap40comprises two opposite pins42suitable for engaging in suitable seats26of the driven holder120constituting a bayonet locking mechanism. The clockwise or anticlockwise rotation given to the safety cap40acting on an external grip element43allows the locking or the release of the bayonet mechanism.

The oscillating dental angle handpiece10according to the invention can be combined with any dental tool to be moved with oscillating motion, like for example files, strips, and polishing tools. The tools described and shown should be taken as examples and not for limiting purposes.

The oscillating dental angle handpiece10according to the invention is assembled by firstly inserting the driven holder20,20′,20″,20′″,120inside the second cavity12B,112B of the hollow housing body12and then axially introducing the driving shaft13inside the first cavity12A of the hollow housing body12until the cam18is introduced into the seat21. The locking cap16inserted from the outside into the hole17of the hollow housing body12and engaged in the annular seat15determines the stable axial positioning of the driving shaft13in the hollow housing body12. The annular configuration of the seat15allows the relative rotation between the driving shaft13and the hollow housing body12.

For angle handpieces10equipped with a shank30made as a separate piece, it is thus inserted in the driven holder and removably or fixedly coupled with it.

The oscillating dental angle handpiece according to the present invention has the advantage of being made entirely from plastic. Therefore, advantageously, the oscillating dental angle handpiece according to the invention is suitable for being used as a disposable angle handpiece.

A further advantage consists of the possibility of easily replacing the driven holder to allow the operator to select the type of fastening of the dental tool that is preferred on each occasion, keeping the other components of the oscillating angle handpiece unchanged. As a result it has great versatility with respect to the possible combinations without penalizing the number of single components to be bought by the operator and to be kept in storage.

The oscillating dental angle handpiece according to the invention is also advantageously equipped with exclusively alternating linear oscillating movement that allows the maximum precision in carrying out dental treatment.

The oscillating angle handpiece thus conceived can undergo numerous modifications and variants, all of which are covered by the invention; moreover, all of the details can be replaced by technically equivalent elements. In practice, the materials used, as well as the sizes, can be whatever according to the technical requirements.