Reciprocating mirror device

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS.
1 and 2, a dental mirror 10 is disclosed which comprises a housing 11, a reflector assembly 12 and a motor assembly 13.
The housing 11 is typically formed from a non-tarnishing material such as stainless steel, includes a handle 14 and a cord member 15.
In the embodiment illustrated in FIGS.
1 and 2, the motion is imparted pneumatically so the handle 14 includes an aperture 16 to accomodate the passage of a fluid; i.
e.
, an air stream.
The aperture 16 serially joins a similar aperture in the cord member 15 (not shown) and cooperates with a port-hole 17 and the handle 14.
Fluid is supplied through the aperture 16 from a suitable source (not shown).
The reflector assembly 12, as shown in FIGS.
2 and 3, comprises a mirror 18, a bearing unit 19, a hub 20 and a turbine 21.
The mirror 18 is rigidly attached to the turbine 21 and the bearing unit 19 is affixed to the housing 11 as by riveting or the like.
As shown in FIG.
3, the turbine 21 includes blades 22 which pass in front of the interior end of the aperture 16.
The bearing unit 19 permits the mirror 18 to rotate when a fluid passes through the aperture 16 and impinges on the blades 22.
When the fluid impinging on the blades 22 is air or the like, rotation of the mirror can be controlled by the operator merely by covering and uncovering the port-hole 17.
When the mirror 18 rotates fast enough, accumulating moisture is flicked away so as to leave the reflecting function unimpaired.
The mirror 18 can be driven by alternate means such as the electromagnetic arrangement illustrated in FIG.
4.
As shown, the hub 20 includes an armature 23 which cooperates with two electromagnets 24.
The electromagnets 24 are energized by wires 25 extending into the housing 11 through the apeture 16.
In the embodiment illustrated, the hub 20 is rotationally anchored by a pair of leaf springs 26.
In operation, when the electromagnets 24 are energized, the armature 23 is attracted to cause rotation of the hub 20 in one direction