Actuating element

This invention relates to an actuating element for controlling an electronic device. Actuating elements are used for controlling the use of different electronic devices. When a predetermined function of the electronic device is to be changed, the actuating element is actuated. When the electronic device is incorporated into a vehicle, e.g. in a dashboard of a vehicle, limited space is provided for controlling the different features and functions of the electronic device. To this end, actuating elements are provided on the front cover facing the passenger compartment with which the driver or any other user can control the different functions of the electronic device. One kind of actuation is the pressing of the actuating element. When an actuating surface of the actuating element is pressed, the actuating force is transmitted to an electronic contact surface by the actual movement of the actuating element contacting a contact surface. Conventionally, these actuating elements are designed as one piece elements in order to make sure that the actuating force is correctly transmitted to the contact surface. When the actuating element consists of several pieces or elements, it may happen that due to the play existing between the different elements, an actuating force is not correctly transmitted to a contact surface. However, it may be preferable, be it of design aspects or be it due to the manufacturing process that an actuating element is desirable comprising more than one piece.

GB 2 247 989 A discloses a push button switch in which the push button is arranged in a cylindrical housing against a spring force between the push button and the cylindrical housing. Resilient locking parts of the push button are engageable with locking tabs on the cylindrical housing to define the outer position of the push button.

US 5 032 698 discloses an actuating element according to the preamble of claim 1.

A need exists to provide an actuating element comprising more than one piece and which nevertheless reliably transmits the actuating force when a user actuates said actuating element.

This need is met by the features of the independent claim. In the dependent claims preferred embodiments of the invention are described.

According to one aspect of the invention, the actuating element for controlling an electronic device comprises a front cover comprising an actuating surface to be actuated by a user. The actuating element further comprises a support structure adapted to be coupled to the front cover, the support structure comprising guiding rips guiding the movement of the actuating element in a housing upon actuation of the actuating element. The front cover additionally comprises centering shoulders which contact the guiding rips for positioning the support structure relative to the front cover when the front cover is coupled to the support structure. Due to the fact that the front cover is coupled to the support structure via the contact of the guiding rips, the guiding rips at the same time guiding the movement of the actuating element a preciseness can be obtained for the guiding of the actuating element in the housing corresponding to the preciseness of a one-piece actuating element. Preferably, the centering shoulders position the support structure relative to the front cover without play. In the present invention, the guiding rips play a double role: First of all, they guide the movement of the complete actuating element upon its actuation, secondly the guiding rips help to fixedly connect the front cover to the support structure. With this double role of the guiding rips a precise guiding of the two-piece actuating element in the housing can be obtained. In case of an actuation, the actuating element reliably transmits the contact force to a contact surface provided behind the actuating element. The contact forces are transmitted as reliably as with the one-piece actuating element.

According to a preferred embodiment of the invention, each centering shoulder contacts a different surface of the guiding rip. When several centering shoulders are provided contacting different surfaces of the guiding rip, the positioning of the front cover relative to the support structure can be obtained in such a way that actually no play is present between the guiding rip and the centering shoulders.

According to one embodiment of the invention, each guiding rip comprises three different guiding surfaces, one centering shoulder being provided for each guiding surface. In this embodiment, the centering shoulders contact the guiding rip at three different sides, so that the position of the support structure relative to the front cover is precisely determined in these three different directions.

Furthermore, the support structure may comprise two guiding rips provided on opposite side surfaces of the support structure. These two guiding rips are positioned in a corresponding guiding structure comprised in the housing in which the actuating element is comprised. With the two opposite guiding rips the actuating element can move in the housing upon actuation.

The support structure may comprise two groups of centering shoulders, one group for positioning one guiding rip, another group for positioning the other guiding rip relative to the cover. When each group of centering shoulders precisely determines the position of the cover relative to the support structure, the position of the support structure is fixed at two different locations, i.e. the locations of the guiding rips. For an interference fit of the guiding rips between the centering shoulders, each centering shoulder may furthermore comprise a projecting rip provided on the surface on which the centering shoulder contacts the guiding rip. These projecting rips on the centering shoulders help to provide a press fit between the guiding rips and the centering shoulders.

Preferably, the centering shoulders are arranged in such a way that two centering shoulders of each group limit the movement of the support structure relative to the cover in a first direction, whereas a third centering shoulder of said group limits the movement of the support structure relative to the cover in a second direction substantially perpendicular to the first direction. In this embodiment of the invention, each group comprises three centering shoulders, so that in total six centering shoulders are provided. In total, four of them restrict the movement in one direction, e.g. the vertical direction, whereas two of the shoulders limit the movement in the horizontal direction.

Preferably, the support structure is coupled to the back surface of the front cover. Accordingly, the centering shoulders project from the back surface of the front cover opposite the actuating surface.

For additionally connecting the front cover to the support structure, some of the centering shoulders may comprise a recess. A projection provided on the support structure can engage this recess for securing the cover to the support structure. Furthermore, it is possible that some of the centering shoulders are arranged substantially parallel to the side surface of the support structure from which the guiding rips extend, whereas other centering shoulders may extend substantially perpendicular to said side surface. However, it is also possible that all the centering shoulders extend substantially parallel to the side surface.

Further objects, features and advantages of the invention will become apparent to those skilled in the art in the course of the following description referring to the accompanying drawings, in which

• Fig. 1 shows a perspective view of a two-piece actuating element comprising a front cover and a support structure,
• Fig. 2 is a perspective view of the back surface of the front cover,
• Fig. 3 is a perspective view of the support structure,
• Fig. 4 is a perspective view of the front cover removed from the support structure, and
• Fig. 5 is an enlarged view showing in more detail the back surface of the front cover.

In Fig. 1 a perspective view of the actuating element is shown. The actuating element comprises a front cover 100 and a support structure 200 which is fixedly connected to the front cover. The actuating element is installed in a housing (not shown) of an electronic device, the actuating element being used for selecting a predetermined feature or function of the electronic device. By way of example, the actuating element may be comprised in a housing of a multimedia system incorporated into a vehicle, the multimedia system comprising a radio receiver, a telecommunication module, a navigation module for guiding a user to a predetermined destination, etc. However, the actuating element is not limited to in-vehicle applications. The actuating element may be used in connection with any electronic device for which an actuating element is necessary to control the functioning of the electronic device.

The support structure 200 has a substantially rectangular housing with two guiding rips 210 on the respective side surfaces of the support structure. The two guiding rips extend along the side surfaces and the guiding rips are used for guiding the movement of the actuating element in the housing of the electronic device (not shown) when a user pushes the actuating element. The support structure 200 is used as a reflector. Light from a light source entering the support structure in an opening 220 is reflected inside the support structure and is used to illuminate the front cover, so that the user is able to locate the front surface or actuating surface 110 of the front cover in a dark environment.

As can be also seen in Figs. 2 and 5, the front cover comprises on its back surface two groups of centering shoulders, a first group 120 and a second group 130. As can be seen especially in Figs. 2 and 5, each group of centering shoulders comprises three different shoulders, the group 120 comprises the centering shoulders 121, 122 and 123, the second group comprising the shoulders 131, 132 and 133. The three centering shoulders of each group are positioned in such a way that they delimit a space in which the guiding rip 210 can be positioned. As can be seen in Figs. 1 and 3, each guiding rip 210 comprises three contact surfaces, the upper contact surface 211, the lower contact surface 212 and the side contact surface 213. As can be seen in Fig. 1, each guiding rip of one group contacts one contact surface 211 to 213 of the guiding rip.

In Fig. 5 the centering shoulders are shown in more detail. Each of the centering shoulders shown comprises on its front surface facing the guiding rip a projecting rip. The centering shoulder 121 comprises a projecting rip 125, the centering shoulder 122 comprises a protecting rip 126 and the centering shoulder 123 comprises a projecting rip 127. These projecting rips are dimensioned in such a way that, when the guiding rip is inserted in the free space between the centering shoulders, a tight fit of the centering shoulders and the guiding rip is obtained. With the provision of the projecting rips a fit without play can be obtained.

The two centering shoulders 121 and 122 limit the movement of the guiding rip and therefore the movement of the support structure in a direction which is shown to be the vertical direction in the figures. The centering shoulder 123, together with the other centering shoulder 133, limit the movement and the play of the support structure relative to the front cover in the direction perpendicular to the vertical direction which, in the embodiment shown, is the horizontal direction.

However, it should be understood that the actuating element can also be inserted into a housing by a 90 degree shift, so that the horizontal direction would be the vertical direction and vice versa.

Referring also to Fig. 1, it can be seen that the two centering shoulders 121 and 122 contact the side surface of the support structure 200. The two centering shoulders contacting the side surface above and below the guiding rip comprise a recess 128 (see Figs. 2 and 5). When the support structure is connected to the front cover by moving the front cover in the direction of the support structure, projections 230 provided on the side surface of the support structure engage the recess for fixedly connecting the support structure to the front cover. As can be seen in detail in Fig. 3, the projections comprise a surface extending substantially perpendicular to the side surface, this perpendicular surface serving as a notch for the recess provided on the centering shoulders. As can be seen in the figures, two projections 230 are provided on each side surface, each projection engaging a recess 128.

In Fig. 4 the front cover 100 is shown detached from the support structure 200. As can be seen, the support structure is a hollow body having a rectangular front surface which is connected to the back surface of the front cover. The front cover comprises a large actuating surface 110 which is actuated by the user.

The support structure comprises an upper side 240 and a lower side 250. When the support structure is connected to the front cover, these upper and lower sides 240 to 250 are received between two additional guiding rips 150 and 160 of the front cover which can be seen in detail in Fig. 2. These two guiding rips provide a guiding of the upper and the lower sides on their outer surfaces as can be seen in Fig. 1, where it is shown that the guiding rip 150 contacts the outer surface of the upper side 240.

The front cover furthermore comprises in its middle part a recessed portion 170 between the guiding rips 150 and 160.

The six centering shoulders together with their projecting rip provided on each centering shoulder allow a tight fit of the front cover on the support structure. This tight fit is obtained by the centering shoulders in connection with the guiding rips, the guiding rips at the same time guiding the movement of the combined actuating element upon activation by the user. Accordingly, the play between the housing and the actuating element depends mainly on the play between the guiding rips and the housing, as the play between the front cover and the support structure can be neglected.