DE19851365A1 - Handpiece with switch and optical cable used to polymerize dental materials employs ring magnet to operate reed switch without hindering rotation of handpiece - Google Patents

Abstract

The optical cable passes through a non-magnetic cylindrical handle. Illumination is controlled by an assembly comprising an annular magnet and e.g. reed switch fixed on the cable, spaced away from the inner wall of the handle. The optical cable (optical fibers or light pipe) passes through a non-magnetic cylindrical handle (6). Illumination is controlled by an assembly comprising an annular magnet (26) and e.g. reed switch (27) fixed on the cable, spaced away from the inner wall of the handle. The annular magnet slides along the tube, closely against its outer wall, to operate the reed switch. The two thin wires (41, 42) from the reed switch, run to the light inlet end. Preferred features: The tube can be turned freely. The wires run inside the optical conductor, but outside its fluid content. The tube has a stop ring, limiting sliding of the magnet. The sliding magnet is encased and spring-biased. Further variants based on these principles are described.

Description

The current second additional application for the main application Az 198 46 580.7 from October 9, 1998 describes a variant of a galvanic hand switch in the broader sense, especially for liquid light guides whose handpiece contains a rotatable hand tube ( 6 ), as shown in FIG. 1.

Fig. 1 shows the light exit end of a liquid light guide in the usual and known dental design. The liquid light guide ( 2 ) consists in wesent union from a carbon-fluoropolymer tube filled with a higher refractive fluid, such as. B. triethylene glycol with some water. For reasons of mechanical reinforcement, the hose made of the lower-refractive CF polymer is located inside a tight-fitting, flexible metal hose (similar to a shower hose), which in turn has been shrunk over with PVC or silicone. The light guide ends at the light exit in a rigid, elongated end piece, over which a tube ( 6 ) is mounted, which is fully rotatably supported along the light guide axis. At the end of this hand tube ( 6 ) there is the curved applicator window ( 7 or 7 a) which is inserted over the end of the light guide ( 8 a), the mechanical fixation being provided via a magnetic ring ( 8 ). The application part ( 7 ) can thus also be rotated along the light guide axis and relative to the hand tube ( 6 ), as indicated in Fig. 1.

Turning the hand tube (6), the curved Applikatorfenster (7a) rotates at which facilitates the dentist holding the tube (6) like a pencil, the application of radiation in situ.

The rotatability of the tube ( 6 ) is so important, especially with liquid light guides, because this light guide is noticeably less flexible than e.g. B. glass fiber bundle light guide and also in contrast to this can only be rotated with great resistance.

That is why optical fibers made of glass fiber bundles always have a rigid, not handpiece rotatable relative to the light guide axis with a handpiece fixed to the handpiece connected, curved applicator window. This fact makes glass easier fiber bundle light guides attaching a galvanically functioning hand switch, with a simple electrical on the handpiece of the light guide Contact switch is located, from which two thin strands run along the light guide be returned to the lamp housing.

The general rule is that in the dental practice when polymerizing with light guide devices the hand switch at the end of the fiber optic is preferred over a foot switch is given because for the dentist working with the hand switch a lot is more pleasant.

In order to make working with the liquid light guide more pleasant for the dentist, the annoying foot switch in the polymerization device is eliminated and the following solution according to the invention of a manual switch for liquid light guide, in particular for those with a rotatable tube ( 6 ), is described.

The variant of the hand switch according to the invention differs from the purely galvanic hand switches which were described in the main application in that the trigger switch on the handpiece of the light guide contains a magnetically activatable switch, a so-called reed switch, and that an annular permanent magnet is also provided, which is characterized by Finger pressure can be moved back and forth along the tubular handpiece ( 6 ), so that the distance between the reed switch and the permanent magnet is reduced or enlarged, and thus the reed switch can be closed or opened, depending on the strength of the magnetic field at the location of the reed switch.

The ring-shaped, movable permanent magnet is preferably connected to a magnet table restoring force, (here e.g. in the form of a second, fixed, ring-shaped Permanent magnets), coupled so that the movable permanent magnet itself automatically moves back to its original position after the Finger pressure and thus also has a defined zero position.

Fig. 2 illustrates the arrangement of the magnetic switch according to the invention at the light exit end of a liquid light guide with a rotatable hand tube ( 6 ), as used in the dental practice for hardening fillings.

The liquid light guide ( 2 ) opens at the light exit end into the rotatable hand tube ( 6 ), which is preferably made of aluminum, plastic, stainless steel or another non-magnetizable material. Between the light guide ( 2 ) and the rotatable hand tube ( 6 ) there is a reed switch or reed contact ( 27 ) which is firmly fixed on the outer jacket of the light guide ( 2 ) at a short distance from the inner surface of the rotatable hand tube ( 6 ) that the hand tube ( 6 ) can rotate freely.

From the reed switch ( 27 ) lead two thin strands ( 41 , 42 ) into the interior of the light guide ( 2 ) and are guided there in the space between the liquid-filled Teflon hose and the outer protective tube to the light entry end of the light guide, where they are led out of the light guide and with shrink tubing, strain relief and electrical connector, e.g. B. in the form of a jack connector.

The trigger ( 10 ) of the switch is in the form of an easily displaceable sleeve which lies closely on the hand tube ( 6 ) and inside which there is a permanent magnet ring ( 26 ). The sleeve ( 10 ) also has a rotationally symmetrical Firiger grip recess ( 28 ) on the light exit side and a corrugation ( 28 a) that runs all the way around the outer circumference.

The sliding sleeve ( 10 ) is preferably made of plastic, which can slide easily on the hand tube ( 6 ), preferably made of aluminum, with an anodized surface. The circular inner diameter of the sleeve ( 10 ) including integrated ring magnet ( 26 ) is stepless and smooth, so that the sleeve ( 10 ) after removing the only magnetically held, curved light exit window (7, Fig. 1) are easily pulled off the hand tube can.

The sliding sleeve ( 10 ) is fixed on the hand tube ( 6 ) of the light guide by a second permanent magnet ring ( 29 ), which has a smaller outer diameter than the permanent magnet ring ( 26 ) and inside the rotatable hand tube ( 6 ), concentric to the magnetic ring ( 26 ) is firmly mounted on the rigid end part of the light guide ( 2 ). The outside diameter of the fixed magnetic ring ( 29 ) is smaller than the inside diameter of the hand tube ( 6 ); so that the hand tube ( 6 ) can continue to rotate freely on its rotary bearing ( 30 ). The permanent magnet rings ( 26 ) and ( 29 ) are both polarized in the direction of their ring axis and are mounted in the assembly so oriented that between the magnetic ring ( 26 ) displaced in the direction of the reed contact ( 27 ) and the magnetic ring located more at the distal end of the light guide ( 29 ) Attraction prevails.

With this arrangement of the magnetic rings ( 26 ) and ( 29 ), a defined rest position of the sliding sleeve ( 10 ) on the hand tube ( 6 ) is created automatically, similar to that shown in FIG. 2, with the sliding sleeve ( 10 ) the two magnetic rings are slightly offset from each other.

If you move the sliding sleeve ( 10 ) and thus the magnetic ring ( 26 ) in the direction of the reed contact ( 27 ) with only slight finger pressure, whereby only a few millimeters of displacement are sufficient, the reed contact ( 27 ) is activated and thus the switching process is not shown here Lamp device triggered. The attraction between the magnetic rings ( 26 ) and ( 29 ) due to the non-magnetic aluminum tube ( 6 ) ensures that the sliding sleeve ( 10 ) automatically snaps back into its initial position after being released.

The magnetic coupling of the sliding sleeve ( 10 ) has the following additional advantages over the coupling of the sliding sleeve ( 10 ) with spring force, as described in the first additional application Az 198 49 569.2:

• 1. Because magnetic attraction forces with minimal distance between the two Permanent magnetic rings are strongest of each other and others Decrease distance quickly, in contrast to elongation or Compression of a spiral spring, a kind of switching threshold arises here, similar to a mechanical light switch. This fact ver reduces the risk of unintentional switching operations.
• 2. Since both the hand tube ( 6 ) and the inner surface of the sliding sleeve ( 10 ) have completely smooth, homogeneous surfaces, and since the sliding sleeve ( 10 ) with the magnetic ring ( 26 ) integrated therein is easily stripped off the hand tube ( 6 ) and can be positioned back on it just as easily, ideal conditions are created for the hygienic requirements in dental operation. Both the hand tube ( 6 ) and the stripped sliding sleeve ( 10 ) can be easily cleaned, even using moist, disinfectant media.

In practical operation, it can be useful to limit the elongation of the sliding sleeve ( 10 ) in the direction of the reed contact ( 27 ) by means of a stopper ring ( 31 ) located on the tube ( 6 ) in the vicinity of the reed contact ( 27 ), but this does affect the hygienic conditions not affected.

For the sake of completeness it should also be mentioned that both rings ( 26 ) and ( 29 ) do not necessarily have to be permanent magnets.

One of the two rings ( 26 ) or ( 29 ) can also consist of magnetizable material, e.g. B. made of magnetizable steel or iron.

In this manual switch in the form of a slide switch with a magnetic restoring force the full rotatability of the wand (6) is maintained, and it can be actuated in any rotational position of the tube (6).

The pencil-like handpiece preferred by some dentists can be opened this way can also be offered with a hand switch.

Claims (7)

1. Optical lighting arrangement consisting of

• 1. a lamp housing comprising an electrical power supply, an optical radiation source, a switch for switching the radiation flow on and off and
• 2. a flexible liquid light guide which can be inserted into the lamp housing and is optically connected to the radiation source and which ends at the light exit end in a rigid end piece via which a fully rotatable tube ( 6 ) is mounted,

characterized in that

• a) the rotatable tube ( 6 ) consists of non-magnetic material,
• b) coaxially and snugly a) displaceable annular permanent magnet or a ring of magnetizable material (26) on the rotary tube (6) axially on the tube (6,
• c) in the inner lumen of the rotary tube ( 6 ) in a fixed position on the light guide ( 2 ) there is a reed switch ( 27 ), spaced from the inner surface of the tube ( 6 ),
• d) two thin strands ( 41 , 42 ) extend from the reed switch ( 27 ), which lead inside the liquid light guide but outside the liquid to the lamp housing and can be electrically contacted there for controlling the radiation flow.

2. Optical lighting arrangement according to claim 1, characterized in that the ring ( 26 ) is inside a on the rotary tube ( 6 ) closely and coaxially but freely displaceable sleeve ( 10 ). 3. Optical lighting arrangement according to claim 1 and 2, characterized in that on the rotary tube ( 6 ) is a stopper ring ( 31 ) which is fixed on the rotary tube ( 6 ), and which the displaceability, the sleeve ( 10th ) in the direction of the reed contact ( 27 ). 4. Optical lighting arrangement according to claims 1-3, characterized in that the sliding sleeve ( 10 ) light exit side has a finger grip ( 28 ) and has a corrugation ( 28 a) all round on the surface. 5. Optical Lighting arrangement according to claim 1-4, characterized in that coaxially with the ring (26), a second ring (29) in the interior of the rotary hand tube (6), but in a fixed position along the axis of the rotary tube (6) is arranged and that at least one of the two rings ( 26 ) and ( 29 ) is a permanent magnet ring, wherein the other ring is also a permanent magnet or can also consist of a magnetizable material. 6. Optical lighting arrangement according to claims 1-5, characterized in that both rings ( 26 ) and ( 29 ) consist of permanent magnets which are polarized along their axis. 7. Optical lighting arrangement according to claim 6, characterized in that the polarization axes of the tube ( 6 ) displaceable magnet ring ( 26 ) and the fixed magnetic ring ( 29 ) point in the same direction.