Operating device for an electrical appliance and electrical appliance having an operating device of this type

Abstract

The invention relates to an operating device for a hob as an electrical appliance, the operating device having an operating element and an operating surface, wherein the operating element is held on the operating surface by means of magnetic force and is movable thereon and is removably positionable. The operating element has an operating element base and an operating element cap arranged on the operating element base and covering said operating element base at the top. The operating element cap is connected to the operating element base and can be rotated relative thereto about a vertical axis of rotation. A plain bearing is arranged between the operating element base and the operating element cap for smooth rotation of the two parts relative to one another. The plain bearing has sliding surfaces extending obliquely at an angle of between 60° and 35° to the axis of rotation.

Description

[0001] Control device for an electrical appliance and electrical appliance with such a control device

[0002] Area of ​​application and state of the art

[0003] The invention relates to an operating device for an electrical appliance, in particular a household electrical appliance such as a hob. Furthermore, the invention relates to such an electrical appliance, in particular a household electrical appliance or hob.

[0004] DE 197 06 169 A1 discloses such an operating device with a rotatable operating element, which is designed as a one-piece unit. The operating element is magnetically centered, rests on the top of a cooktop, and can be rotated. Its outer area features several signal magnets that rotate via magnetic field sensors located beneath the cooktop. This allows the angle of rotation to be precisely detected.

[0005] EP 2 693 290 A1 discloses another operating device with a rotatable operating element. This operating element is constructed in two parts and is rotatable within itself. A lower inner operating element base sits, so to speak, stationary on a control surface. Rotatably mounted on this base is a control element cap, whose rotation can be detected on the control element base. A ball bearing is provided between the two parts to ensure smooth rotation.

[0006] Task and solution

[0007] The invention is based on the object of creating an operating device as mentioned above and an electrical device provided therewith, with which problems of the prior art can be solved and, in particular, it is possible to create a practical operating element for good and comfortable operation of an electrical device.

[0008] This object is achieved by an operating device having the features of claim 1 and by an electrical device provided with such an operating device having the features of claim 15. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. Some of the features are explained only for the operating device or only for the electrical device equipped with it. However, they are intended to be able to apply independently and independently of one another to both such an operating device and such an electrical device. The wording of the claims is incorporated into the content of the description by express reference.

[0009] The operating device for an electrical appliance, which can advantageously be a household electrical appliance such as a hob, has an operating element and an operating surface. The operating element can be positioned on the operating surface or placed on the operating surface, thus being removable. The operating element is held there by magnetic force, while being movable and remaining there. Advantageously, the operating element is placed on the operating surface at a single precise location for subsequent operation by moving or rotating the operating element.

[0010] The control element comprises a control element base and a control element cap arranged on this control element base, which covers it from above or upwards. The control element cap is connected to the control element base and can be rotated relative to it about a rotation axis that preferably runs vertically or perpendicularly to the operating surface. Thus, the control element cap and control element base can be rotated relative to each other, whereby during operation, the operator should have the impression that only the control element cap is present, which is mounted on the electrical device or operating device so that it can be rotated as desired.

[0011] According to the invention, a plain bearing is provided for mounting the control element base on the control element cap or between the control element base and the control element cap, which ensures as smooth a rotation of the two parts as possible relative to one another. This allows the operator to easily rotate the control element cap as a whole, i.e. the part of the control element to which it engages, which increases operating comfort. However, the plain bearing should not be a completely random plain bearing; rather, it should have sliding surfaces that run at an angle oblique to the axis of rotation. This allows mounting in both horizontal and vertical directions, meaning that the control element cap is mounted precisely in both horizontal and vertical directions on the control element base and thus on the operating device and the electrical device. Such an oblique angle is advantageously between 85° and 30°, particularly advantageously between 60° and 35°.The use of a plain bearing has the great advantage of being easy and inexpensive to manufacture, requiring little maintenance, and being permanently reliable. The inclined position of the sliding surfaces ensures support in two different or perpendicular directions, meaning no additional bearing is necessary. In one embodiment of the invention, the plain bearing can carry or absorb a force acting from above via the control element cap onto the control element base, thus forming a vertical bearing. Thus, in this direction in particular, it can form the only contact area between the control element cap and the control element base, meaning there is no contact at any other point.

[0012] In a further embodiment of the invention, the plain bearing can be or form the only contact surface or the only contact between the control element base and the control element cap. This enables a simple design while simultaneously reducing or avoiding unnecessary friction, allowing the control element cap, which is within the operator's grasp, to be easily rotated.

[0013] The plain bearing is advantageously ring-shaped and concentric to the axis of rotation, which promotes rotation. The plain bearing has a cap sliding ring at the top with a cap sliding surface on its downward-facing underside. The cap sliding ring is arranged at the bottom of the control element cap or on a downward-facing side of the control element cap, which does not have to be the very bottom side of the control element cap. The control element cap advantageously overlaps the control element base laterally outwards and downwards. Furthermore, the plain bearing has a base sliding ring at the bottom with a base sliding surface on its upward-facing upper side, wherein the base sliding ring is arranged at the top of the control element base, advantageously in the upper region of the control element base.

[0014] Particularly advantageously, the cap sliding surface and the base sliding surface rest on or against each other circumferentially, thus forming the sliding bearing. Preferably, the two sliding surfaces are annular or circular, closed, and also continuous.

[0015] In a further development of the invention, a support surface between the cap sliding surface and the base sliding surface can have a width between 0.5 mm and 5 mm. Such a width is preferably between 1 mm and 3 mm. For an exemplary diameter of the plain bearing between 20 mm and 40 mm, a sufficiently large overall support surface can be achieved for good bearing function with low friction and, at the same time, good rotational guidance. The support surface or the cap sliding surface and / or the base sliding surface advantageously have a width that should remain constant in the circumferential direction.

[0016] There are two options for designing an inclined position of the sliding surfaces. According to an advantageous first option, the base sliding surface is designed such that it rises from radially inward to radially outward. The cap sliding surface also rises correspondingly from radially inward to radially outward, so that the sliding surfaces are, so to speak, V-shaped to one another. Preferably, the cap sliding surface and the base sliding surface are designed congruently to one another as truncated cone annular surfaces. According to an alternative second option, the sliding surfaces can slope from radially inward to radially outward, so that they are designed in exactly the opposite way, or, so to speak, inverted V-shaped to one another.

[0017] Preferably, the plain bearing or sliding surfaces of the plain bearing are made of plastic, eliminating the need for metal. This simplifies manufacturing and integration, especially when the control element is preferably made primarily of plastic. A plastic can preferably be selected from the group of PTFE, POM (also known under the brand name Delrin), and PET. Additional sliding additives can be used, meaning the sliding surfaces may even be lubricated.

[0018] In an advantageous embodiment of the invention, a plain bearing can be designed with the largest possible diameter for the most stable support. However, this requires very precise manufacturing of the plain bearing. Furthermore, the required amount of material is greater. Finally, it may then be difficult for the control element cap to cover the control element base, so that the latter is, so to speak, invisible when actuated. Therefore, the plain bearing can be provided with a significantly smaller radius than the control element. Preferably, the plain bearing can have a radius between 30% and 70% of the maximum radius of the control element, particularly preferably between 40% and 60%, or even just between 40% and 50%.

[0019] The control element is advantageously designed such that the control element cap and the control element base are captively connected to one another. They thus form an integral structural unit such that when the control element cap is lifted and / or moved, the control element base remains connected to it and can be moved together with it, except that the two parts can necessarily be rotated relative to one another. A holding device can be provided for the connection, which can even be released again under certain circumstances. It should be possible to create this at least once during assembly of the control element. Detachability can be advantageous for cleaning the interior of the control element, particularly the plain bearing, and possibly for repairs.The holding device then connects the control element cap to the control element base, whereby it should advantageously not generate any friction when the control element cap rotates relative to the control element base, i.e. when the control element cap rests on the control element base by means of the plain bearing. In an advantageous embodiment of the holding device, it can be a snap-in connection so that it can at least be easily manufactured. In this case, snap-in projections can be arranged at the top of the control element cap and snap-in recesses at the bottom of the control element base so that snap-in projections engage behind the snap-in recesses. At least the snap-in projections can be made of metal, whereby they have an elasticity that is advantageous for a snap-in connection and a strength that is advantageous for the holding effect. In a simple embodiment, they can be made of plastic, which can also advantageously apply to the snap-in recesses.

[0020] To provide haptic feedback to an operator when operating or rotating the control element, rotary detent means can be provided between the control element cap and the control element base for a rotary detent when the control element cap and the control element base rotate relative to each other. These directly effect rotation only in certain steps, or can at least convey this haptic impression to an operator. Such a rotary detent or corresponding rotary detent means are preferably designed with equal detent spacing for consistent operation by rotation.

[0021] The rotary locking means advantageously comprise an elastic circumferential ring with at least one projection, preferably with two to four projections. This at least one projection can be rounded or even partially spherical. The rotary locking means can have a counter surface with a plurality of recesses adjacent to one another for the at least one projection. The projection can be pressed against the counter surface either vertically or horizontally, advantageously elastically. However, this is generally known.

[0022] In a further development of the invention, the operating element can have a light guide with which light signals can be generated on an upper side and / or lateral outer side. The light guide is preferably made of light-conducting plastic and runs at least partially through the operating element cap, in particular to its upper side and / or outer side. The light guide can run in the operating element cap to its underside so that light can be coupled in from below or from beneath the operating surface. A light guide can run in particular past the operating element base. Alternatively, it can be split in two, with one partial light guide running through the operating element base and another partial light guide running through the operating element cap. A light guide can be relatively narrow, alternatively wider or even formed as a ring on the upper side of the operating element cap.In an advantageous development of the invention, the control element cap and / or the control element base can be manufactured using multi-component plastic injection molding. The sliding bearing or sliding surfaces can be injected at the same time, advantageously also from a specially suitable plastic.

[0023] Preferably, signal magnets are arranged in the control element cap, and magnetic field sensors are arranged beneath the control surface to detect rotation of the control element cap. The signal magnets and magnetic field sensors are preferably arranged such that the signal magnets move over the magnetic field sensors when the control element cap is rotated. For this purpose, reference is made to the prior art mentioned above.

[0024] To secure the control element to the control surface, it should have at least one holding magnet, preferably in the center or in a central area. A holding magnet can be provided in the control element base or in the control element cap. It should be as close as possible to the control surface or to a magnet located beneath the control surface, with which it cooperates to hold it.

[0025] Preferably, the control element is electrically passive, meaning it contains neither active components such as sensors, active lighting devices such as LEDs, communication devices, or control devices, nor its own power source. This allows for a simple design.

[0026] An advantageous electrical appliance comprises a previously described operating device, which itself or with its operating surface forms an outer surface of the electrical appliance. This can, in particular, be the top surface of a hob or other electrical household appliance.

[0027] These and other features emerge not only from the claims but also from the description and the drawings. The individual features may be implemented individually or in combination in an embodiment of the invention and in other fields, and may represent advantageous and individually protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the generality of the statements made therein.

[0028] Brief description of the drawings

[0029] Embodiments of the invention are schematically illustrated in the drawings and explained in more detail below. The drawings show: Fig. 1 is a plan view of a hob according to the invention as an electrical appliance with an operating device according to the invention including a rotatable operating element,

[0030] Fig. 2 is a schematic side view of an operating device according to the invention with a rotatable operating element on the hob plate of the hob from Fig. 1 and

[0031] Fig. 3 is an enlarged detailed view showing the structure of a plain bearing, a locking connection and a rotary locking mechanism.

[0032] Detailed description of the implementation examples

[0033] Fig. 1 shows a plan view of a hob 11 according to the invention, which forms an electrical appliance according to the invention. The hob 11 has a hob plate 12 with a top side 13 and a bottom side 14, as shown in Fig. 2. Four cooking zones 16a to 16d are provided on the hob 11 in a conventional manner. In the front central area, the hob 11 has an operating device 18. This has several operating buttons 20 designed as touch switches and a seven-segment display 22. This could also be implemented with a display.

[0034] In a central area, the operating device 18 has an operating element 24 according to the invention, which is designed for operating the hob 11 by rotation. It can be rotated for operation, as will be explained below. It can also be removed from the surface of the operating device 18 easily and without great effort, as will also be explained below.

[0035] For details of a rotary control with an operating device according to the invention, reference is generally made to the prior art, for example, that mentioned above. The design details of the illustrations will be explained further below.

[0036] The basic structure of an operating device 18 according to the invention with an operating element 24 according to the invention is explained with reference to Fig. 2. The operating element 24 has a relatively small operating element base 26. Its underside 27 is placed on the upper side 13 of the hob plate 12 on the operating device 18. It should remain as stationary as possible, which is why this underside 27 can also be provided with a rubber or silicone coating, for example. The operating element base 26 is designed like a ring and has a base sliding surface 29 in the radially outer area at the top for a slide bearing 28. This can be designed in any desired shape on the operating element base 26; one possible embodiment is shown in Fig. 3, which will be explained in more detail below.The underside 27 of the control element base 26 also forms the lowest level of the control element 24, which is why only it should rest on the top side 13 of the hob plate 12.

[0037] The control element cap 31, with a cover 32, which can be made largely of plastic, aluminum, or stainless steel, rests on the control element base 26 and projects upwards and, above all, laterally beyond it. A central region, in which a centering magnet 33 is arranged, projects into a central opening of the ring-shaped control element base 26. It is advantageously positioned at a short distance from the top side 13 of the cooktop plate 12.

[0038] Further radially outward, several signal magnets 34 are provided in the lower area of ​​the control element cap 31, preferably arranged in a ring shape and evenly distributed. For example, there may be 6 to 12 signal magnets 34.

[0039] One or more optical fibers 36 run between the central centering magnet 33 and the signal magnets 34, possibly as a single continuous component. However, they can also be segmented in the circumferential direction. The optical fiber 36 is advantageously attached or molded into the other material of the control element cap 31. Furthermore, the optical fiber 36 has coupling points 37 on the downward-facing side of the central region of the control element cap 31. On the upper side of the control element cap 31, it has coupling points 38, which can penetrate the casing 32.

[0040] Opposite the base sliding surfaces 29, cap sliding surfaces 39 are formed at the bottom of the control element cap 31. These are angled in the same way as the lower base sliding surfaces 29; they are parallel and lie fully against one another. The sliding surface between them is therefore a circumferential, uninterrupted ring with a width of, for example, 1 mm or 2 mm and a diameter of 20 mm to 30 mm. The angled position ensures that the control element cap 31 is always centered and maintained relative to the control element base 26. This creates a smooth pivot bearing that is reliable, precise, and comfortable in operation. The base sliding surface 29 and cap sliding surface 39 can be formed by areas of the respective parts made of their material. Special materials can advantageously be provided; for this purpose, reference is made to Fig. 3 and the following description of the figures.

[0041] Further functional units of the control device 18 are arranged beneath the hob plate 12, which serves as the control surface. This includes a large holding magnet 41, which forms the counterpart to the centering magnet 33, so that the two are strongly attracted to each other. Rotating the control element cap 31 together with the centering magnet 33 does not change this.

[0042] Magnetic field sensors in the form of Hall sensors 42 are arranged radially outside the holding magnet 41 on the underside 14 of the cooktop plate 12. There may be two or three such Hall sensors 42, for example. They detect a rotation of the control element cap 31 with the signal magnets 34 contained therein above it, specifically a direction of rotation and an angle of rotation. This is generally known from the prior art. For this purpose, the Hall sensors 42 are connected to an operating control 44. This could also be part of a control system for the cooktop 11 itself.

[0043] The control panel 44 is also connected to two LEDs 45 shown, which are also located on the underside 14 of the cooktop panel 12, but can also be 4 to 10 LEDs. They are arranged directly opposite the coupling points 37 of the light guide 36 in the control element cap 31 and, depending on the operating state, can couple light into the light guides 36 at the coupling points 37. This is self-explanatory, generally known from the prior art, and therefore needs no further explanation here.

[0044] The control element 24 in Fig. 2 is designed as a structural unit in that the control element cap 31 cannot actually be easily separated from the control element base 26. The more detailed illustration in Fig. 3 shows how this can be achieved in practice.

[0045] Fig. 3 shows a more detailed illustration of a slightly differently designed operating element 124. This operating element 124, like the operating element 24, can be used on the operating device in Fig. 2. The operating element 124 also has an operating element base 126, which is designed as a structural unit or partial structural unit. The operating element base 126 has an underside 127. This underside is rubberized or provided with a similar coating or treatment so that it cannot be easily moved on the upper side 13 of the cooktop plate 12 according to Fig. 2. The operating element base 126 can, for example, be made of plastic. It has a large central opening, as is actually the case in Fig. 2. In the outer area, a base sliding ring 130 is inserted or injected as a 2-component injection-molded part. The base sliding ring 130 is made of a special plastic material, for example POM orDelrin, thus, exhibits very good sliding properties with very low sliding friction. A base sliding surface 129 formed on the base sliding ring 130 has a constant width and is uninterrupted in its circumferential direction. This base sliding surface 129 is at an angle of approximately 30° to the horizontal plane or to the top side 13 of the cooktop plate 12. The width of the base sliding surface 129 is similar to that previously mentioned for Fig. 2, for example, 1 mm for a diameter of 20 mm.

[0046] The control element cap 131, in turn, has a shell 132 and a central centering magnet 133. Several signal magnets 134 are provided in the radially outer region. A rotational axis D of the control element 124 is shown in dash-dotted lines; it runs through its center. The fully illustrated left half of the control element 124 is mirror-symmetrical to the right half.

[0047] A light guide 136 runs through the control element cap 131, with a coupling point 137 on a bottom side and a coupling point 138 on a top side. In this respect, this corresponds to the design shown in Fig. 2.

[0048] The control element cap 131 also has a cap sliding surface 139 formed on a cap sliding ring 140. This cap sliding ring 140 is attached as a separate part to the underside of the control element cap 131 in this area, for example, molded onto it as previously explained for the lower base sliding ring 130. The choice of material can either be the same or the same, i.e., both sliding surfaces can be made of the same material. Alternatively, the best possible material combinations can be used, which together exhibit very low friction when sliding against each other.

[0049] For a snap-in connection 147 between the control element base 126 and the control element cap 131 mentioned above, a circumferential metallic snap-in ring 149 can be attached, for example, glued or injected, to the underside of the control element cap. It advantageously has downwardly projecting, elongated snap-in hooks 150, which are provided at some distance from one another in the circumferential direction and are individually formed. These snap-in hooks 150 initially extend slightly downwards before extending radially inwards again. They engage behind snap-in projections 152 on the control element base 126, which are arranged slightly radially outside the base sliding surface 129 or the base sliding ring 130. Such a snap-in connection 147 can be designed such that it is created automatically when the control element cap 131 is placed onto the control element base 126, advantageously by pressing it on with some force.The locking connection 147 can then also be designed such that it can no longer be released without causing damage, i.e., it is fixed. This ensures that the operating element cap 131 and the operating element base 126 cannot be accidentally released or detached from one another. As an alternative to the locking connection 147 shown here, screwable or otherwise detachable connections between the operating element cap 131 and the operating element base 126 could also be provided. Fig. 3 also shows that a series of upwardly extending incisions and projections is provided radially within the plain bearing 128, which are intended to prevent moisture from penetrating beyond them into the interior of the operating element 124. They form a type of labyrinth seal.

[0050] A rotary detent 154 is also provided radially within the slide bearing 128. On an underside of the control element cap 131, several detent notches 155 are provided along a circle, which advantageously directly adjoin one another in a manner known per se. Spring-loaded detent projections 157 are provided on the control element base 126, which are spring-loaded upwards, for example, two or three detent projections. They can be evenly distributed in a circle. When the control element cap 131 is rotated relative to the control element base 126, a rotary detent effect occurs, so that the control element cap 131 and the control element base 126 are rotated in small detent steps. This generates haptic feedback for the operator, which subjectively represents more comfortable operation.

[0051] Instead of the radially outward and radially upward inclination of the base sliding surface 129 and cap sliding surface 139 shown here, they could also be designed radially outward and downward. This would also ensure centering of the control element cap 131 relative to the control element base 126. Angles of inclination of the sliding surfaces in the aforementioned and initially mentioned range are considered advantageous, since the force load is presumed to be primarily vertical and less horizontal.

Claims

Patent claims 1. Operating device for an electrical appliance, in particular for a household electrical appliance, with: an operating element, an operating surface, wherein: the operating element is held on the operating surface by magnetic force and can be moved and removably positioned thereon, the operating element has an operating element base and an operating element cap arranged on the operating element base and covering it from above, the operating element cap is connected to the operating element base and can be rotated relative to it about an axis of rotation, preferably about a vertical axis and / or an axis of rotation arranged at a right angle to the operating surface, characterized in that a sliding bearing is provided and arranged between the operating element base and the operating element cap for smooth rotation relative to one another, the sliding bearing has sliding surfaces running at an angle oblique to the axis of rotation, in particular at an angle between 85° and 30°.

2. Operating device according to claim 1, characterized in that the plain bearing is the only contact surface between the operating element base and the operating element cap.

3. Operating device according to claim 1 or 2, characterized in that the sliding bearing carries a force acting from above by means of the operating element cap onto the operating element base, wherein in particular the sliding bearing forms the only contact area between the operating element cap and the operating element base in this direction.

4. Operating device according to one of the preceding claims, characterized in that the sliding bearing is annular and concentric to the axis of rotation, the sliding bearing comprising: at the top a cap sliding ring with a cap sliding surface on its downwardly facing underside, which is arranged on the operating element cap, and at the bottom a base sliding ring with a base sliding surface on its upwardly facing upper side, which is arranged on the operating element base.

5. Operating device according to claim 4, characterized in that the cap sliding surface and the base sliding surface rest on one another or abut one another circumferentially, preferably in a closed ring shape.

6. Operating device according to claim 4 or claim 5, characterized in that a support surface between the cap sliding surface and the base sliding surface has a width between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, wherein in particular the support surface or the cap sliding surface and / or the base sliding surface have a constant width in the circumferential direction.

7. Operating device according to one of claims 4 to 6, characterized in that the base sliding surface is designed to rise from radially inside to radially outside and the cap sliding surface is designed to rise correspondingly from radially inside to radially outside, wherein preferably the cap sliding surface and the base sliding surface are designed congruent to one another as truncated cone ring surfaces.

8. Operating device according to one of the preceding claims, characterized in that the sliding bearing or sliding surfaces of the sliding bearing are made of plastic, wherein the plastic is preferably selected from the group: PTFE, POM, PET, in particular with additional sliding additives.

9. Operating device according to one of the preceding claims, characterized in that the operating element cap and the operating element base are captively connected to one another and form an integral structural unit such that when the operating element cap is lifted and / or moved, the operating element base remains connected to it and moves together with it.

10. Operating device according to claim 9, characterized in that a holding device, which is in particular detachable, connects the operating element cap to the operating element base without generating friction when the operating element cap rotates relative to the operating element base when the operating element cap rests on the operating element base by means of the sliding bearing.

11. Operating device according to claim 10, characterized in that the holding device is a locking connection, wherein locking projections are preferably arranged at the top of the operating element cap and locking recesses are arranged at the bottom of the operating element base.

12. Operating device according to one of the preceding claims, characterized in that rotary locking means are provided between the operating element cap and the operating element base for a rotary locking upon relative rotation of the operating element cap and the operating element base to one another, wherein the rotary locking is preferably designed with equal locking intervals.

13. Operating device according to one of the preceding claims, characterized in that the operating element has a light guide, wherein the light guide runs at least partially through the operating element cap, in particular to its upper side and / or lateral outer side, wherein preferably the light guide leads in the operating element cap to its underside, in particular past the operating element base.

14. Operating device according to one of the preceding claims, characterized in that the operating element cap and / or the operating element base are manufactured by multi-component plastic injection molding, preferably with injected sliding bearings or injected sliding surfaces.

15. Electrical appliance with an operating device according to one of the preceding claims, characterized in that the operating surface forms an outer side of the electrical appliance, in particular an upper side of a hob as an electrical appliance or of another electrical household appliance.

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