This invention relates to an electrical switch and in particular, to a switch for mounting to a surface and having a seal for sealing the switch to the surface.
Sealed electrical switches are principally used outdoors or in industry, where they must be shielded from environmental elements, such as water, whether it be spray or pressurized water, chemicals or dust. These elements create high demands on the sealing in the switching region. The fields of use for switches of this type are very diverse and range for example from use in shipbuilding, in craft and gardening devices through to use in construction machines.
Switches of the type mentioned above are known inter alia from EP1581959B1. Here, a toggle switch is described, which has a seal, which is arranged around a bushing. The switch upper part has a spacer with projections, in order to prevent too strong a compression of the seal. The switch is suitable to be mounted into an opening located in a plate. The switch is fastened by means of a screw connection.
Defective mounting of sealed switches often leads to a loss of function of the seal. Thus, for example, the seal can be compressed too strongly or too weakly, which can lead to damage of the seal or to a reduction of the sealing function. In addition, it may occur in the case of incorrect mounting, that the switch is not permanently fastened on the installation region, as fastening elements are not completely locked for example. This is problematic to a certain extent in the case of the mounting of switches in openings of components, as the latching region is not visible and thus it is not possible to investigate correct mounting by visual inspection.
Hence there is a desire for an electrical switch of the type described at the beginning, in which a functionally suitable mounting of the switch and thus also of the seal is indicated by a noticeable optical feature.
Accordingly, in one aspect thereof, the present invention provides an electrical switch for mounting into a surface of a component, which has a shoulder region. The shoulder region has at least one region with at least one assigned indicator component, wherein this assignment is changed in terms of position in the case of complete sealing action of the seal compared to an incomplete sealing action of the seal. The indicator components give an option for investigating the correct mounting of the switch. To this end, the assignment of the indicator component to the region of the shoulder region is changed in terms of the position thereof, as soon as the seal is compressed to an extent that a complete sealing action is ensured. The indicator component can in this case be joined directly to the shoulder region or be brought close to the region of the shoulder region. The positional change of the assignment of the indicator component can for example take place in the form of breaking off, bending, penetration, displacement or the like and can in this case be reversible or else irreversible. The seal, which is assigned to the opening in the surface of the component, is preferably realized as a round seal, for example as an O-ring, or else a rectangular configuration of the seal is possible. During installation, the seal is compressed between the surface of the component and the shoulder region of the switch. This seal seals the region between the opening of the component and the switch, so that no media or contaminants can reach the interior of the component. The switch has a housing, which is sealed against environmental influences. In the region of the electrical connection lines, this seal is preferably provided by means of encapsulation with plastic. The region between the operating component and the switch housing is sealed by means of an internal seal, preferably an O-ring.
Preferably, the switch has at least one stop, which determines the minimum spacing between the lower edge of the shoulder region and the surface of the component. The stop is integrated into the switch housing in the shoulder region and is constructed as a projection. For mounting, the shoulder region is brought closer to the surface, until there is contact between the stop and the surface, wherein the spacing between the shoulder region and the surface of the component, predetermined by the stop, is slightly smaller than the provided compression height of the seal. By means of this arrangement, it is effected that the seal is compressed to the correct extent, in order on the one hand to ensure a complete sealing action by means of sufficient compression and on the other hand to prevent damage to the seal by means of too strong a compression.
In a particularly preferred development of the invention, the shoulder region has at least one indicator component, which is connected via a predetermined breaking point to the shoulder region and which is brought closer to the surface of the component in such a manner that the indicator component is changed in terms of position, preferably removed, in the case of complete sealing action of the seal. In the state, in which the switch is inserted into the opening, but has not yet been pushed down, the indicator component rests on the installation region. By bringing the shoulder region of the switch closer to the surface of the component, the seal, which can advantageously be realized as an O-ring, is compressed. When resting the stop on the surface of the component, the seal is compressed to such an extent that a complete sealing action is produced and the indicator component is changed in terms of position, in that it for example breaks off or bends at the predetermined breaking point. The indicator component is preferably installed laterally adjacently to the seal at the shoulder region and is constructed flat. The correct installation of the switch is indicated by the absence of the indicator component. Owing to the absent indicator component, the view onto a region of the switch housing or the shoulder region or the seal, which was covered by the indicator component before the installation, can also be cleared.
In a particularly preferred embodiment of the invention, the indicator component is constructed as at least one frame, which is arranged around the shoulder region of the switch and the upper edge of which is changed in terms of position with respect to the upper edge of the shoulder region, preferably is flush with the upper edge of the shoulder region, in the case of complete sealing action of the seal compared to an incomplete sealing action of the seal. A reversible variant of the indicator component is represented by this arrangement. It is provided that the frame is arranged around the opening of the component, into which the switch should be installed, and the switch is assembled into the opening through the frame. The shoulder region and the frame can be moved with respect to one another. If the shoulder region of the switch is brought closer to the surface of the installation region by pushing down the switch, then the upper edge of the shoulder region and the upper edge of the frame are displaced with respect to one another. The switch has a stop which, when resting on the surface of the component, predetermines the minimum spacing between the shoulder region of the switch and the surface of the installation region. The spacing is dimensioned in such a manner that a seal arranged between the shoulder region and the surface is compressed to a suitable extent for a complete sealing action. Preferably, the upper edge of the frame and the upper edge of the shoulder region are constructed in such a manner that the same are flush with one another in the case of a complete sealing action of the seal. The correct installation of the switch is therefore indicated by a displacement of frame and shoulder region with respect to one another.
In a further embodiment of the invention, the shoulder region has at least two depressions on the outer wall surrounded by the frame and the frame has at least one elevation on the inner surface thereof adjacent to the outer wall of the shoulder region, so that at least one elevation engages into a first depression in the case of incomplete sealing action of the seal, and that at least one elevation engages into a second depression in the case of complete sealing action of the seal. Preferably, the two depressions are arranged above one another at the edge of the shoulder region. In the non-installed state, one elevation engages on the inner surface of the frame, for example into the lower depression on the side wall of the shoulder region. If the switch is then pressed down, then the elevation on the inner surface of the frame is pushed from the lower depression into the upper depression. In order to ensure a displacement of the elevation from the lower into the upper depression, both the depression and the elevation have soundings to some extent, which are adapted to one another in terms of the shape thereof. A releasable latching is obtained owing to the partially round construction of the depression and the elevation. Thus, in this case, one is concerned with a reversible variant of the installation indicator. The correct installation of the switch is indicated by means of a change of the spacing between the upper edge of the switch and the upper edge of the frame.
Of course, the elevation may be formed on the shoulder region and the depressions formed in the frame.
In a further embodiment of the invention, the spacing between the upper edge of the shoulder region and the second depression is equal to the spacing between the upper edge of the frame and the elevation, so that the upper edge of the shoulder region is flush with the upper edge of the frame in the case of complete sealing action of the seal. A simple-to-investigate indicating feature of the correct installation is obtained, owing to the flushness of the upper edge of the shoulder region and the upper edge of the frame. In this case, the frame can for example be colored in a noticeable manner, in order to allow a simple inspection of the displacement of frame and shoulder region.
Advantageously, at least one movable visible component is assigned to the switch, which has at least one indicator component, which is constructed as a projection and the projection is assigned to at least one region of the shoulder region with a lower material thickness than the other regions of the shoulder region and the projection can penetrate this region in the case of complete sealing action of the seal, so that sections of the projection are visible. The visible components have a flat constructed region, which rests on the surface of the component, when although the switch is inserted, the seal is not compressed. The projections emanate from this flat constructed region. The visible component can be displaced with respect to the shoulder region, for example in the perpendicular direction to the surface of the component. The projections of the visible component, which are assigned to the regions with lower material thickness of the shoulder region, are advantageously constructed in a tapered manner. During the compression of the seal, for example by pressing down the switch, the assigned projections penetrate the thin regions of the shoulder region. The penetrated regions of the shoulder region therefore clear the view onto the preferably noticeably colored projection of the visible component. In the case of correct mounting, a visible and lasting feature is obtained, which indicates the sealing action of the seal. Alternatively to the pointed embodiment of the projections, the projections can also be shaped in such a manner that the same are inserted into the surface of the shoulder region after the penetration of the assigned region on the shoulder region. The shoulder region then has a smooth, planar surface. The correct installation is indicated by colored regions on the surface. An additional indicator component can also be obtained, in that the region on the shoulder region, which is assigned to the projections of the spacer, only has a lower material thickness than the remaining shoulder region at the edge. A molding is surrounded by this edge, which is removed during the penetration of the shoulder region by the projections of the spacer. The pressed out molding is proof for the correct installation of the switch, thus it functions as a checking component.
In an alternative embodiment of the invention, the indicator component and the seal are realized as one piece and the sealing region of the part is obtained by means of at least one flexible elevation, to which a depression is assigned in the shoulder region. In this case, a projection of the part is assigned to a region of lower material thickness of the shoulder region. The projection can be configured in a pointed manner, so that when inserting the switch into the opening of the component, the region of low material thickness on the shoulder is penetrated by the projection and so correct mounting is indicated. The sealing region can be obtained by means of resilient projections, which are brought closer to one or a plurality of depressions of the shoulder region. When inserting the switch into the opening of the component, the projections of the part can be compressed by the shoulder region, so that the same have a sealing action. Preferably, polyethylene with a high density (HDPE) is used as material for the part.
In a further embodiment of the invention, the seal has at least one elevation, which is assigned to at least one indicator component on the shoulder region, wherein the indicator component is connected via a predetermined breaking point to the shoulder region and the elevation is brought closer to the indicator component in such a manner that the indicator component is changed in terms of position in the case of complete sealing action of the seal. The seal has two regions, one region with sealing function, which is assigned to the shoulder region of the switch, and one region, which is constructed as a projection, which is assigned to an indicator component on the shoulder region. When the sealing region is compressed to such an extent that a sealing function results, the indicator component on the shoulder region is pressed against the projection and thus removed, for example. The correct mounting of the switch is therefore indicated for example by means of the absence of the indicator component.
To simplify the switch mounting, in a design development, the shoulder region and the seal can be constructed as one piece and the piece can have at least one indicator component connected to the part by means of a predetermined breaking point and the indicator component can be brought closer to the surface of the component in such a manner that the same is changed in terms of position in the case of complete sealing action of the seal. In the state, in which the switch is inserted into the opening of the component, but the seal is not yet compressed, the indicator component and the sealing region of the part rest on the surface of the component, whereas the remaining regions of the part do not yet have contact to the surface. By means of further approaching of the part to the surface of the component, the seal is compressed and the indicator component is removed, bent or otherwise changed in terms of position at the predetermined breaking point provided therefor. The strength of the compression of the seal is in this case determined by the non-sealing regions of the part, which therefore function as a stop. When the same rest on the surface of the component, the correct strength of the compression of the seal is reached.
A reversible variant of the installation indicator is obtained in that the seal has at least one projection, which is assigned to at least one opening in the shoulder region of the switch, so that the projection is visible from the outside in the case of complete sealing action of the seal. In the case of correct mounting of the switch, the seal is therefore sufficiently strongly compressed, the projection on the seal passes through the openings in the shoulder region of the switch and thus becomes visible from outside. The penetration of the preferably noticeably colored projection is an indicator for the correct installation of the switch. In this embodiment of the invention, the indicator component is restored to the original state thereof during the disassembly of the switch. It is also possible, depending on the fastening method, to install and disassemble the switch multiple times without losing the possibility of indicating the correct installation.
Preferably, the switch has at least one snap-fit connection. Preferably, two or more snap-fit connectors are used. The snap-fit connectors are arranged laterally on the switch housing and are flexibly designed. The clamping lengths of the snap-fit connectors are dimensioned such that the same can only engage below the surface of the installation region if the seal, for example an O-ring is compressed in terms of height. When the seal has been compressed to a satisfactory extent, the snap-fit connectors engage and the switch is correctly mounted. As the satisfactory compression of the seal is indicated by indicator components, these indicator components are also a hint as to the correct engagement of the snap-fit connectors. Installation regions of the surface of components can have different thicknesses. The same can be adapted to the clamping lengths of the snap-fit connectors by spacers with different thicknesses. The mounting by means of snap-fit connections is particularly time-saving, as the switch only has to be inserted into an opening of the component and pressed down until the snap-fit connections engage. In addition, no tools are required for mounting. The mounting of the switch using snap-fit connections is a very durable fastening, as an independent release of the connection is virtually excluded. A force is exerted by the snap-fit connections, which acts perpendicularly to the surface of the installation region of the component. Advantageously, the snap-fit connectors are arranged in such a manner in this case that the line of action of the force thereof runs through the center of the cross section of the seal. Thus, an optimal distribution and utilization of the force is achieved, which leads to a best-possible sealing action of the seal. By adding further snap-fit connections, the force distribution to the seal can be optimized further.
In a development of the invention, it is provided that the snap-fit connections are arranged in groups and the snap-fit connections in the groups have different clamping lengths from one another. Switches can be mounted in installation regions of different thickness by means of these arrangements. In each group, the snap-fit connection engages with the appropriate clamping length for the installation region in each case on the underside of the installation region. For secure mounting, the clamping length is to be chosen to be as short as possible in this case.
An alternative fastening method for the switch is obtained in that the switch has at least one thread and at least one nut, wherein the nut is arranged on the opposite side of the surface of the component to the seal. For mounting, a spacer can be laid below the shoulder region of the switch and the switch can be screwed from below using the nut.
In a development of the invention, at least one movable visible component and the shoulder region are constructed in such a manner that when assigning the two components to one another, the movable visible component and the shoulder region constitute a lateral boundary in each case and thus a groove is formed, which is suitable to accommodate the seal. In one exemplary embodiment, a lateral boundary facing the opening is represented by the shoulder region of the switch and a lateral boundary facing away from the opening is represented by the spacer. A lateral slipping of the seal, which can for example be constructed as an O-ring, is excluded by the groove formed. An optimal force action of the connecting pieces on the seal results due to the lateral fixing of the O-ring and the corresponding arrangement of the snap-fit connections.
A preferred embodiment of the invention will now be described, by way of example only, with reference to figures of the accompanying drawings. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same reference numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.
a is a partially cutaway, perspective view of a non-installed switch according to
b is a partially cutaway, perspective view of an installed switch according to
Illustrated in
An electrical switch according to
An electrical switch according to
An exemplary embodiment is shown in
In
A further exemplary embodiment of the invention is illustrated in
The exemplary embodiment according to
An exemplary embodiment of the invention according to
An exemplary embodiment of the invention is illustrated in
An exemplary embodiment of the invention according to
An exemplary embodiment of the electrical switch according to
A detail view of the engagement between the frame 18 and the shoulder region 7 is illustrated in
A detail view of the engagement according to
An exemplary embodiment of the invention according to
The arrangement of the indicator component 11, the stop 7a, the seal 6 and the shoulder region 7 is schematically illustrated in
All of the features mentioned in the above description and in the claims can be combined in any desired selection with the features of the independent claim. The disclosure of the invention is therefore not limited to the described or claimed feature combinations, rather all sensible feature combinations in the context of the invention are to be considered as disclosed. Also, the scope of the invention is to be determined by reference to the claims that follow.
In the description and claims of the present application, each of the verbs comprise, include, contain and have, and variations thereof, are used in an inclusive sense, to specify the presence of the stated item but not to exclude the presence of additional items.
Number | Date | Country | Kind |
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102013009263.9 | Jun 2013 | DE | national |
This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 10 201 300 9263.0 filed in Germany on Jun. 5, 2013, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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61832334 | Jun 2013 | US |