Electrical appliance housing

The present invention relates to a housing, for example an electrical appliance housing or other, possibly water-tight housing with a housing body of hard plastic, in which an opening for actuating a switch or the like is provided inside the housing body, the opening being provided with a membrane made of plastic Is closed and an actuating button is provided for actuating the switch on the diaphragm.

Electric toothbrushes or other electrical appliances such as shaving appliances, kitchen machines and the like generally have a watertight housing, within which switches are often arranged, so that the actuating energy for such switches must be directed through the housing wall in such a way that no water can penetrate. In a conventional arrangement, the corresponding switch or the brake or clutch to be actuated or the valve or transmission to be actuated etc. lies behind an opening of the housing wall, which is closed by a resilient membrane. To switch the device, the user presses the membrane with a finger and thus actuates the switch below. The membrane consists of a soft plastic and is materially connected to the housing wall consisting of hard plastic,

Such device housings are shown in FIG <patcit id="pcit0001" dnum="US6093900A"><text>U.S. Patent No. 6,093,900</text></patcit>, in the <patcit id="pcit0002" dnum="EP0684020A"><text>EP 0 684 020</text></patcit> Or in the <patcit id="pcit0003" dnum="EP0692215A"><text>EP 0 692 215</text></patcit> disclosed.

As an optical and tactile reference to the underlying switch, the membrane often bears an increase or a different spatial structure on the outside. However, a disadvantage of this construction is that the spatial structure consists of the same substance as the membrane and thus has the same color. This reduces the recognizability.

It has therefore already been provided in known devices for inserting an actuating button made of metal into a continuous hole in the membrane. However, it is disadvantageous in this case that water can penetrate through the hole into the housing interior. The water tightness of the housing is no longer present.

SUMMARY OF THE INVENTION The present invention is therefore based on the object of providing an improved electrical appliance housing of the initially mentioned kind which avoids disadvantages of the prior art and advantageously develops the latter. In particular, an actuating button is to be connected to the diaphragm so that no water can penetrate through the housing wall.

According to the invention, this object is achieved by an electrical appliance housing according to claim 1. Preferred embodiments of the invention are the subject matter of the subclaims.

According to the invention, the actuating button is fastened to a base made of hard plastic, which is materially connected to the membrane. The base of hard plastic is hermetically connected to the membrane, so that no water can penetrate into the housing interior, preferably the base and the membrane being made of material-related plastics in order to ensure a good connection. The actuation button can be made of different materials, without the need for a close connection of the diaphragm with the diaphragm and the actuation button for reasons of a tight connection to the membrane. The membrane can be injection-molded onto the hard plastic base by a two-component injection molding process.

In a further development of the invention, the base carrying the actuating button is connected to the housing body of hard plastic material by way of at least one elastic web. The elastic web is preferably formed in a material-homogeneous manner and in one piece with the housing body and / or the base. In particular, the base, which at least one web and the housing body can be injection-molded in one piece from plastic, for example polypropylene or ABS, can be injection-molded. The elastic web, via which the base is connected to the housing body, not only facilitates the positioning of the base in the opening in the housing body when the elastic membrane is injected. In addition, the elastic web supports the membrane, which is particularly advantageous in the case of large-area membranes, which are otherwise liable to wrinkle or to give great flexibility.

In order to achieve an absolute watertightness of the housing in the region of the actuating button, the base on which the actuating button is seated is formed free of through-openings. The operating button does not at all penetrate the base completely, so that there is no through opening from the outer side of the base to the inner side of the base.

The membrane can not only enclose the base on its jacket surface, but in principle could also partially cover the front sides of the base so that the base would be poured into the membrane. Preferably, however, at least the end face of the base facing the outside of the housing is free from overlapping by the membrane. On the end face of the base, which faces the outside of the housing, a recess is provided in the diaphragm which corresponds more or less to the front face of the base. According to a preferred embodiment of the invention, the base penetrates the membrane from its outer side to its inner side, ie the end face of the base, which faces the inner side of the housing, is not covered by the membrane.

The aforementioned at least one elastic web which connects the base to the housing body could basically be cast into the membrane. In order to obtain an attractive appearance, the at least one elastic web does not lie on the outer side of the membrane. The web preferably lies on the inner side of the membrane. This is advantageous not only for optical reasons, but also provides a support for the membrane when pressed with a finger-shaped dome.

In order to achieve good optical and tactile perceptibility of the actuating button, the actuating button is designed to be raised against the membrane.

According to an embodiment of the invention, the actuating button and the base are preferably separate components and joined together so that they can consist of different materials. While the base preferably consists of the material of the housing body, the actuating button can be made of metal, ceramic, glass or else plastic.

The operating button and the base can be joined together in various ways. According to a preferred embodiment of the invention, the base has a blind hole in which the actuating button is accommodated with a shaft-shaped section. The shaft-shaped section can be pressed, glued or poured into the blind hole. In order to prevent the actuating button or the shank from being detached from the blind hole, at least one radial rib and / or a bead can be provided on the shank. Such a radial projection digs into the wall of the blind hole in the base so that extraction is impossible.

In order to achieve a permanent connection between the actuating button and the base, the actuating button can also be welded to the base.

In an alternative further development of the invention, the actuating button and the base can also be embodied in one piece in a material-homogeneous manner. The base forms the operating button at the same time.

In particular, when the actuating button is subsequently fitted with the base and protrudes outwards via the latter, it is important that no dirt can penetrate between the membrane and the actuating button. According to a preferred embodiment of the invention, it is therefore provided that the membrane has a rim section which surrounds the base and protrudes beyond the base to the outside of the device and which lies in a press-fit or preferably against a rim section of the actuating button. When the actuating button is joined to the base, the edge portion of the membrane is deformed so that an interference fit is achieved between the actuating button and the membrane. In order not to detach the membrane from the base by this pressure, The base can preferably have a radial projection, preferably a peripheral shoulder, on which the diaphragm is seated on its end facing the inside of the housing. If, then, the operating button is placed on the base from the outside and the edge portion of the membrane is compressed, the radial projection on the base catches the corresponding pressure on the membrane. The diaphragm is compressed between the radial shoulder of the base and the radially projecting edge of the actuating knob. The radial projection on the base catches the corresponding pressure on the membrane. The diaphragm is compressed between the radial shoulder of the base and the radially projecting edge of the actuating knob. The radial projection on the base catches the corresponding pressure on the membrane. The diaphragm is compressed between the radial shoulder of the base and the radially projecting edge of the actuating knob.

The edge section of the diaphragm, which protrudes towards the outside of the housing before the actuating button is pressed, can form an annular collar which bears against the end face on the underside of the actuating button.

Alternatively, the edge section of the membrane around the base can also define a recess coaxial to the base and adjoining the latter, into which the actuating button is inserted in a precisely fitted manner. The recess of the diaphragm and also the underside of the actuating knob can also be tapered in order to achieve a full seating of the actuating button on the diaphragm, the recess preferably having a smaller cone angle than the cooperating lower side of the actuating button portion.

In order to achieve a better support of the membrane in the case of a large-area membrane, at least one cantilevered diaphragm support in the form of a wing or a thin plate or the like can preferably be attached to the base and / or to the at least one elastic web. The membrane is thereby supported not only by the surface of the elastic web itself, but also by the additional surface of such a cantilevered diaphragm support. Irrespective of the mechanical effect, such a cantilevered plate or the corresponding vane can also be molded on the sock or the membrane in order to achieve a special optical effect.

The base can also be connected to the edge of the housing opening by means of several elastic webs. This also ensures a better support of the membrane.

Expediently, the diaphragm is not only materially connected to the base which carries the actuating button but also to the housing body. The membrane is injection-molded onto the edge of the corresponding housing opening in the two-component injection molding process.

Further objects, advantages, features and possible applications of the present invention will become apparent from the following description of preferred exemplary embodiments with reference to the drawings. All the described and / or pictorially illustrated features form the subject matter of the present invention by themselves or in any desired combination, also independent of their summary in the claims or their back-links. In the drawings:<dl id="dl0001"><dt>FIG</dt><dd>4 shows a section through the housing body of an electrical appliance housing along the line AA in FIG <figref idrefs="f0001">FIG</figref>, Which shows a section of the housing body with an opening and a base for fixing an actuating button arranged therein,</dd><dt>FIG</dt><dd>A plan view of the housing body and the opening provided therein <figref idrefs="f0001">FIG</figref>,</dd><dt>FIG</dt><dd>A sectional view of the housing body <figref idrefs="f0001">FIG</figref>, The housing opening being closed by a resilient membrane and an actuating button being shown before its attachment to the base in the housing opening,</dd><dt>FIG</dt><dd>A section of the housing body similar <figref idrefs="f0001">FIG</figref>, Which shows the operating button in the attached state,</dd><dt>FIG</dt><dd>A section similar to the <figref idrefs="f0001">Figures 1, 3 and 4</figref> Of an electrical appliance housing according to an alternative embodiment of the invention, in which the actuating button is joined by means of a sonotrode with the base arranged in the diaphragm, </dd><dt>FIG</dt><dd>A section similar <figref idrefs="f0001">FIG</figref> A further preferred embodiment of an electrical appliance housing which shows a tapered actuating button before joining with the base arranged in the diaphragm,</dd><dt>FIG</dt><dd>A section similar <figref idrefs="f0001">FIG</figref> A further preferred embodiment of an electrical appliance housing,</dd><dt>FIG</dt><dd>A section similar <figref idrefs="f0002">FIG</figref> A further preferred embodiment of an electrical appliance housing,</dd><dt>FIG</dt><dd>A section similar to the <figref idrefs="f0001">FIGS</figref> and <figref idrefs="f0002">6</figref> Of an electrical appliance housing according to a further preferred embodiment of the invention in which the actuating button is shown before joining with the base arranged in the diaphragm and is joined by friction welding to the base,</dd><dt>FIG</dt><dd>A section of the electrical appliance housing <figref idrefs="f0003">FIG</figref>, Which shows the operating button in the state fitted with the base,</dd><dt>FIG</dt><dd>A section similar to the preceding figures of a further preferred embodiment of the invention, in which the actuating button is injection-molded onto the base in a two-component injection molding process,</dd><dt>FIG</dt><dd>A section similar to the preceding figures of a further preferred embodiment of the invention of an electrical appliance housing in which the actuating knob is constructed in a material-homogeneous manner with the base,</dd><dt>FIG</dt><dd>A section similar <figref idrefs="f0001">FIG</figref> Of a housing body of an electrical appliance housing according to a preferred embodiment of the invention, in which two pedestals for accommodating two actuating buttons are arranged in a housing opening, the section being taken along the line BB in FIG <figref idrefs="f0004">FIG</figref> Is made,</dd><dt>FIG</dt><dd>A top view of the housing body <figref idrefs="f0004">FIG</figref>,</dd><dt>FIG</dt><dd>A section similar to the <figref idrefs="f0001">FIGS</figref> and <figref idrefs="f0004">13</figref> Of a housing body of an electrical appliance housing in which a base for accommodating an actuating button in a housing opening is formed on the housing body by means of two elastic webs, the section along the line CC in FIG <figref idrefs="f0004">FIG</figref> Is made,</dd><dt>FIG</dt><dd>A top view of the housing body <figref idrefs="f0004">FIG</figref>, </dd><dt>FIG</dt><dd>A plan view similar <figref idrefs="f0004">FIG</figref> To a housing body according to a further embodiment of the invention in which a plate-shaped membrane support is formed on the base, and FIG</dd><dt>FIG</dt><dd>A plan view similar to the <figref idrefs="f0004">FIGS</figref> and <figref idrefs="f0005">17</figref> To a housing body according to a further embodiment of the invention, in which a plurality of membrane supports are shaped in the form of wings on the base and web in the housing opening.</dd></dl>

The <figref idrefs="f0001">Figures 1 to 4</figref> Show the housing 1 of an electric toothbrush or similar electrical appliance with a housing body 2 made of a hard plastic such as, for example, polypropylene or ABS, in the wall 3 of which an opening 4 is formed which has an approximately rectangular outline with rounded corners in the drawing. However, it is understood that the opening 4 may also have other shapes.

From the edge of the opening 4, a thin web 5 projects into the opening 4, which is part of the housing body 2. As<figref idrefs="f0001">FIG</figref> , The web 5 is integrally formed on the wall 3. At the free end, the web 5 carries a base 6 which is aligned approximately centrally with respect to the opening 4 and has an approximately cylindrical contour in the illustrated embodiment. At its end facing the inside 7, the base 6 has a radially projecting shoulder 8 (cf.<figref idrefs="f0001">FIG</figref>).

The web 5, which extends parallel to the plane of the opening 4, lies approximately on the lower edge of the opening 4, which is located towards the inside 7.

The housing body 2 including the web 5 and the base 6 as well as the opening 4 are produced by injection molding. In a second injection process, a membrane 9 is injected into the opening 4 via the web 5 and around the base 6. As<figref idrefs="f0001">FIG</figref> , The diaphragm 9 has a low elevation 10 in the form of a collar extending annularly about the base 6. The membrane 9 consists of a soft plastic such as, for example, TPE. In the injection molding process, this soft plastic materially joins with the hard plastic of the wall 3 of the housing body 2 and of the web 5 and base 6 molded thereon. The plastics of the housing body 2 including the web 5 and base 6 and the membrane 9 are materially related, A good connection is achieved. As<figref idrefs="f0001">FIG</figref> The thickness of the diaphragm 9 is less than the thickness of the wall 3. The surface of the diaphragm 9 facing the outer side 11 is lower than the level of the wall 3 of the housing body 2 surrounding the opening 4. The housing body 2 thus has in the region of that of FIG Of the diaphragm 9 is a slight depression.

Attached to the base 6 is an actuating button 12 which is approximately mushroom-shaped. The actuating button 12 comprises a head 16 and a shaft-shaped neck 17, on which a sharp-edged, radially protruding rib 18 is formed. The actuating button 12 can be made of metal such as steel, stainless steel, aluminum and the like or else a very hard plastic or else ceramic or glass. The surface can be refined by electroplating, anodic oxidation, etching, coating, dyeing, grinding or blasting and the like. Instead of the one rib 18, a plurality of ribs can also be arranged axially one behind the other on the shaft-shaped neck 17.

As the <figref idrefs="f0001">3 and 4</figref> , The operating button 12 is cold-pressed into a blind hole 19 formed in the base 6, the rib 18 being anchored in the wall of the blind hole 19. In this case, By placing the actuating button 12 on the base 6, the elevation 10 of the diaphragm 9 between the shoulder 8 of the base 6 and the head 16 of the actuating button 12 is compressed. The resultant pressing prevents the penetration of dirt between the membrane 9 and the head 16 of the actuating button 12.

In order to facilitate the pressing of the neck 17 into the blind hole 19, the actuating button 12 can be heated before pressing. If the actuating button 12 is made of metal, it can be heated by induction in a high-frequency electric field.

Alternatively, the actuating button 12 can also be pressed into the blind hole 19 of the base 6 by means of a sonotrode in the form of a tappet 20, which oscillates at an ultrasonic frequency, as shown in FIG <figref idrefs="f0002">FIG</figref> shows. The ultrasonic vibration is transmitted to the actuating button 12, whereby the hard plastic of the base 6 at the contact point with the actuating button 12 is heated by friction. This facilitates the penetration of the neck 17 and the rib 18 into the blind hole 19 as well as the flow of the plastic into the annular space between the head 16, neck 17 and rib 18. After cooling, the actuating button 12 is fixedly connected to the base 6. As<figref idrefs="f0002">FIG</figref> The diaphragm in this embodiment does not have a ramp-like elevation about the base 6 but rather a recess 21 corresponding in contour to the head 16 of the actuating button 12 in which the head 16 fits snugly after being inserted into the base 6.

For the version according to <figref idrefs="f0002">FIG</figref> Both the head 16 of the operating button 12 and the recess 21 in the diaphragm 9 have a cylindrical contour. Alternatively, as shown in FIG<figref idrefs="f0002">FIG</figref> , The recess 21 in the diaphragm 9, which adjoins the base 6 axially towards the outside, can be conical and extend towards the outer side 11 at an angle α. The head 16 of the operating button 12 is tapered. It tapers towards the neck 17 at the angle β, which is preferably greater than the angle α of the recess 21. In addition, the largest diameter D is also₂ Of the head 16 is somewhat larger than the corresponding diameter D₁ Of the recess 21. After the pressing of the actuating button 12, the soft plastic of the membrane 9 is tensioned in the vicinity of the head 16, which prevents the penetration of dirt into the recess 21.

As an alternative to the previously described embodiments, the neck 17 of the actuating button 12 can also be formed smooth, ie, free of projections. As<figref idrefs="f0002">FIG</figref> , The neck 17 fits snugly in the blind hole 19 of the base 6 and is stuck therein. The recess 21 of the diaphragm fits the head 16 of the actuating button 12.

In a further variant of the actuating button 12, the <figref idrefs="f0002">FIG</figref> , Its neck 17 carries an annular bead 22 instead of the previously described sharp-edged rib 18. The actuating button 12 is in this case cast into the base 6. The actuating button 12 is inserted into the injection mold so that the neck 17 and the bead 22 are injection-molded with hard plastic during the injection molding of the housing body 2. Subsequently, in the second casting step, the membrane 9 of soft plastic is formed by two-component injection molding.

The operating button 12 does not necessarily have a neck 17 connected to the head 16. The<figref idrefs="f0003">Figures 9 and 10</figref> Show an embodiment in which the actuating button 12 consists merely of the head 16, the underside of which is preferably flat. The base 6 is somewhat raised against the diaphragm 9 so that the actuating button 12 can be connected to the base 6 by welding, for example friction welding. Preferably, the base 6 and the actuating button 12 are made of the same plastic or of mutually related plastics, whereby both parts can be differently colored. If the actuation button 12 is made of ABS, a decorative metal layer can be applied to the visible surfaces before welding by electroplating. How a comparison of the<figref idrefs="f0003">Figures 9 and 10</figref> The base 6 is slightly removed during friction welding with the actuating button 12, so that the underside of the actuating button 12 rests flush on the upper side of the membrane 9 after joining.

As <figref idrefs="f0003">FIG</figref> , The operating button 12 can also be attached to the base 6 in the two-component injection process. The actuating button 12 consists of a hard plastic, which is preferably at least closely related to the plastic of the base 6 in order to achieve a good connection during injection molding. By the separate injection of the actuating button 12, the latter can be given a different color from the housing body 2, so that a good visibility is achieved. The membrane 9 is formed in a third injection molding process.

The execution according to <figref idrefs="f0003">FIG</figref> Shows an actuating button 12, which is formed by the base 6 itself. The actuating button 12 is thereby produced as a continuation of the base 6 during the injection molding of the housing body 2. The diaphragm 9 is formed around the actuating button 12 in the second injection process. In this embodiment, the housing body 2 and the operating button 12 have the same color. However, the visibility of the operating button 12 can be very good when the diaphragm 9 has a different color. This embodiment is distinguished by a particularly inexpensive manufacturability.

As the <figref idrefs="f0004">Figures 13 and 14</figref> It is, of course, possible to arrange two bases 6 in the opening 4 of the housing body 2, so that two actuating buttons can be attached. As a result, a plurality of functional elements located underneath the membrane can be actuated. It is also possible to switch on one switch underneath with the one operating button and to switch off the same switch with the other actuating button. As the<figref idrefs="f0004">Figures 13 and 14</figref> , The two pedestals 6 are each arranged on a separate web 5, which each extend from the wall 3 of the housing body 2 into the opening 4. In this way, independent of the influence of the diaphragm 9, independent actuation of the actuating buttons, which are fastened to the two pedestals 6, is possible.

According to another embodiment of the invention, the base 6 is supported in the opening 4 by two webs 5. As the<figref idrefs="f0004">FIGS. 15 and 16</figref> , The two flat webs, which are arranged in a common plane parallel to the plane of the opening 4, are arcuate or wavy in order to keep the bending resistance transversely to their plane. They extend towards opposite edges of the opening 4. After injection molding the webs 5 and the base 6 with a membrane, the base 6 can receive an actuating button in the manner described above.

In particular for aesthetic reasons, a large-area diaphragm 9 in the housing body 2 can be required. However, there is the danger that the diaphragm 9 deforms and forms, for example, bumps or folds. In order to provide a remedy, a diaphragm support 23 which projects out parallel to the plane of the opening 4 can be formed on the web 5 and / or the base 6. As<figref idrefs="f0005">FIG</figref> A diaphragm support 23 in the form of a thin plate can be attached to the base 6 and the web 5, the plate being arranged approximately concentric with respect to the opening 4. According to the design according to<figref idrefs="f0005">FIG</figref> A plurality of membrane supports 23 may also be provided in the form of fingers or wings which extend in the plane of the opening 4 from the base 6 and transversely away from the web 5. After injection molding the webs 5, the base 6 and the membrane supports 23 with a membrane made of plastic, the base 6 can receive an actuating button in the manner described above.

In the above-described embodiments, the actuating button 12, including the head 16, the neck 17 and the rib 18 or bead 22, are of circular cross-section. However, an uneven cross-section can also be provided in order to anchort the actuating button 12 in the base 6 in a rotationally fixed manner. A directional symbol, such as, for example, an arrow indicating the direction of pressure and / or the effect of the actuation of the actuating button 12 can be provided on the actuating button 12.

In the embodiments described above, the wall 3 of the housing body 2 and the diaphragm 9 are essentially flat. However, it is understood that, alternatively, curved walls or diaphragms may also be provided.