Abstract:
The invention relates to a mobile device ( 10 ) for activating at least one switch element ( 40 ) that is arranged inside a housing ( 11 ), having a key unit ( 20 ) that comprises at least one contact means ( 21 ), wherein the contact means ( 21 ) is aligned to the interior ( 12 ) of the housing ( 11 ) in order to activate the switch element ( 40 ), and having a receptacle ( 13 ) arranged on the housing ( 11 ) to which the key unit ( 20 ) is fastened. According to the invention, the receptacle ( 13 ) comprises a force transfer region ( 14 ) that is arranged between the key unit ( 20 ) and the switch element ( 40 ) such that the interior ( 12 ) of the housing ( 11 ) is protected from the outer region ( 2 ).

Description:
TECHNICAL FIELD 
     The invention concerns a mobile device for the activation of at least one switching element that is arranged inside a housing, with a keypad which has at least one contacting device, whereby the contacting device is directed towards the inside of the housing so as to activate the switching element, and a receptacle that is arranged on the housing on which the keypad is fixed. 
     BACKGROUND 
     In DE 101 21 045 C2, an ID-transmitter is disclosed, in which a keypad is fixed within a housing. A plunger is mounted on the keypad. On operation, this plunger serves to activate a switching element, by which the elastic key is moved by the plunger against the switching element. The keypad is fixed to an edge of a support. The support has snap-on elements which serve in fixing on the housing. The ID-transmitter shows to its advantage that it can be mounted safely and easily, whereby at the same time a perfect sealing is achieved, since the keypad completely closes the opening of the housing. 
     BRIEF SUMMARY 
     It is the task of the present invention to make a mobile device, whereby the effort required during manufacture and/or during assembly is further reduced and at the same time a perfect sealing is achieved, particularly in the region of the housing of the key unit. 
     As per this invention, it is envisaged that the receptacle has a force transmission area that is positioned between the key unit and the switching element in such a way, that the interior of the housing is protected from the outer area. If the key unit is activated from the outside by the user, particularly if the user presses on the key unit, a corresponding movement of the contacting device takes place in the direction of the interior of the housing, whereby at the same time the contacting device acts on the force transmission area. With that, the force transmission area is momentarily deformed in the direction of at least one switching element that is inside the housing, particularly elastically and/or flexibly deformed, due to which a corresponding contact with the switching element takes place. Since the force transmitting element fully separates the interior area from the outer area of the mobile device, it is ruled out that moisture, dirt particles, etc. can ingress into the region of the housing in which the key unit is located. Thus, as a rule, the electronics inside the mobile device, inclusive of circuit board, switching elements, sensors, battery, etc. are simply and effectively sealed from the outer areas, whereby at the same time the assembly of the key unit in the receptacle is simplified, since the fastening of the key unit lies completely in the outer area of the mobile device and therefore there are no particularly stringent requirements for the fastening of the key unit to the housing to ensure a sealing of the interior of the housing. 
     In one possible version of the invention, the housing and the force transmission area can form a combined, two-component structural element. The force transmission area is located, at least in certain zones, in the receptacle of the housing. In this embodiment of the invention, the housing and the force transmission area advantageously form a monolithic structural element, so that the interior of the housing is fully separated from the outer area of the mobile device by the monolithic structural element. The two-component structural element thus fully encapsulates the interior area of the mobile device, which includes, among other things, electronic components. Due to this, a reliable sealing can be achieved. 
     An advantageous design of the invention could be such that the force transmission area is made out of a first material and the housing out of a second material, whereby the first material has a lower mechanical resistance than the second material. The first material and/or the second material could be made up of a mixture of plastics. In an advantageous version of the mobile device, the first material can be a silicone or a thermoplastic polymer. The force transmission area of the receptacle can, for example, be made out of a thermoplastic elastomer (TPE) or a thermoplastic elastomer on urethane basis (TPU). 
     One measure to improve the invention could be that the key unit is at least made out of a flexible and/or elastic key element and a support which is, at least partially, surrounded by the flexible key element. Here, the key unit includes at least two parts, made up of the support and the key element. The key element can in turn include a number of individual keys, and in particular, an array of individual keys. It is advantageous to assign each individual key a contacting device which in turn communicates with a switching element or else which, on the corresponding activation of the key unit by the user, acts on the respective switching element. The support is advantageously a type of frame for the key element, whereby the key element completely surrounds and covers the support towards the outside area, so that the fixing of the support to the receptacle of the housing is not visible to the user. 
     It can be of advantage that the key element is stretched over the support, particularly that the key element is pulled over and/or turned up like a stocking over the support. During the application of the flexible key element, the material of the key element is stretched in such a way that the key element can completely surround the geometry of the support. In the fixed state, the key element is stretched on the support, whereby the inner side of the key element is in contact with the surface of the support. In a possible version of the invention, the inner area of the support which is turned away from the outer side of the mobile device is, at least in places, not surrounded by the key element. This means that the key element does not interfere, at least at some section of the support that is turned towards the force transmission area. This section is thus designed free of key elements. 
     In addition, it can be of advantage to ensure that the key element is designed with at least one contacting device that can extend through a gap of the support, whereby particularly several contacting devices are planned each of which extend due to varying gaps of the support. The gap or gaps can take on different geometric shapes, for example round, square, angular, polygonal. The contacting device is expediently adapted to the geometric shape of the gap, whereby in one possible version of the invention the contacting device is shaped like a plunger and through the respective gaps, extends in the direction of the force transmission area. Advantageously, the free end of the contacting device can be spaced apart from the force transmission area, whereby it is expeditious that the spacing is small. A contacting of the free end of the contacting device with the force transmission area takes place only when the appropriate key unit is operated, through which, due to a deformation of the force transmission area, the switching element is activated. Similarly, it is conceivable that the free end of the contacting device touches the force transmission area even if the key unit is not operated. 
     It is further conceivable that the support at least has a depression in which a gap is envisaged, whereby at least a section of the depression has a stop function for the key element. Here, it is particularly of advantage that the depression of each gap has a special geometry that serves as a stop for the key element, particularly for each individual key so as to prevent damage, particularly to the switching element, in case the key element is pressed in too far. 
     Expediently, the force transmission area separates the interior of the housing completely from the outside area. Thus all particles, in particular moisture, dirt etc., are prevented from ingression into the interior of the mobile device in which, for instance, there could be susceptible electronic parts. 
     In a possible version of the invention, the force transmission area can be designed to be laser transparent, whereby the key unit is laser welded to the force transmission area, in particular that the support is laser welded to the force transmission area. Alternatively, it is conceivable that at least one area of the key element which can extend up to the force transmission area is laser welded to the force transmission area. Advantageously, the material of the force transmission area should be transparent to laser radiation. The part that is to be joined to the force transmission area, particularly the key element or the support, has a material that is designed to absorb laser radiation. In this possible design of the invention, the energy of the laser beam is conveyed through the part to be joined that is transparent to laser radiation, in particular the force transmission area, onto the jointing plane in which the jointing surfaces of the parts to be joined are located. The jointing plane is the boundary layer area between the two parts to be joined, in this case the force transmission area and the support or the key element. There, the electromagnetic energy from the absorbing part to be joined can be converted without loss into heat energy. The energy introduced leads to plasticization of the absorbing part. The transparent part to be joined can also be plasticized through heat conduction. Advantageously, a positive firm bonding takes place between the two parts to be joined. A thin melt film of 10 to 400 μm is formed in the boundary layer. Due to the contactless and locally confined energy supply by way of laser radiation, thermal damage to the joined parts is prevented. Mechanical loading is also avoided since there is no movement relative to each other of the parts being joined during the introduction of energy and the cooling process. The achievable firm bonding features itself in impermeability, freedom from pores and a high level of optical quality and, depending on the pairing of the materials of the parts being joined, in the region of the basic strength of the base materials. 
     It has been seen that CO 2 —, Nd:YAG—and diode lasers are particularly suited to joining the parts to be joined. The wave length of a CO 2 —laser limits optical penetration depths to very small values in the parts to be joined, which are transparent to diode lasers. It has been seen that the optical gap depths can be well adjusted by high pigmentation of the parts to be joined. The advantage of laser welding in comparison with other jointing methods such as adhesive bonding, in which fumes are released, is in the negligible pollution of the workplace. When using high powered diode lasers, the emission wavelengths lie in the region of 800 to 1,000 nm, which can be conveyed, for instance, through optical glass fibers. The glass fiber inserts enable a simple integration of laser and optical processing systems e.g. in a robotics system which, on the one hand can adjust the housing, the key unit and/or the key element in the receptacle and on the other simultaneously introduce the corresponding energy through laser radiation onto the parts to be joined. 
     It is conceivable that the receptacle is designed as a depression in the housing in which the key unit is located. It can be of further advantage that the surface of the key unit runs almost flush with the surface of the housing. This leads to a very satisfying tactile response (haptic). 
     The assembly effort is simplified by the fact that the key element is fixed without adhesive onto the support. The key element is only stretched over and/or slipped over the support. The key element is finally located on the support and is held onto this securely and without slippage. 
     Further, it can be provided for that the housing has an upper and a lower part, whereby the key unit is fixed to the upper part. The upper lower parts can be form-locked and/or force-locked and/or fused to each other. The interior of the mobile device is securely sealed off by the upper and lower parts. 
     Advantageously, the key element is made elastic is such a way that, after a corresponding activation of the switching element by the contacting device, the key element returns elastically to its original position when a force is no longer acting on the key element from outside. The individual keys of the key element, which can be arranged next to each other, can be separated from each other by appropriate haptic elements. The haptic elements advantageously possess material properties that are different from the individual keys. The haptic elements advantageously form a common structural element with the individual keys, in this case particularly the key element. The haptic element can, for example, be made as a rib or as a grove like depression between the individual keys. 
     Advantageously, the key element has a protective varnish on the outside. This protective varnish can protect against weather conditions, scratches etc. 
     In an advantageous embodiment of the invention, the mobile device is an ID-transmitter for a keyless activation of a locking device of a motor vehicle. In this connection, the ID-transmitter can communicate with a passive access authorization system, particularly an access and drive authorization system, of the motor vehicle. For instance, the vehicle and the ID-transmitter can exchange codes with each other, whereby the communication between the ID-transmitter and the motor vehicle can take place over a wireless signal. In particular, the signals are sent out inductively. To advantage, for reasons of safety, the signals can be cryptologically encoded. The said communication can be started manually by key stroke on the ID-transmitter, particularly on the key element, or alternatively without active operation, that is, passively controlled. To ensure that the motor vehicle can be used if the electronics of the ID-transmitter fail, the ID-transmitter appropriately also has a purely mechanical emergency key. 
     In this case the invention concerns a process for the assembly of a mobile device for the activation of at least one switching element that is arranged inside a housing, with a key unit that has at least one contacting device, whereby the contacting device is directed towards the interior of the housing to be able to activate the switching element, and a receptacle arranged on the housing in which a key unit is fixed. Of particular advantage in this case is that in an initial step, a flexible key element is stretched on a support, from which the key unit is built up. In a further step, the key unit is inserted into the receptacle. Finally, the key unit is laser welded, whereby at least a section of the receptacle is made laser transparent. Beside the simple assembly of the mobile device, the mobile device distinguishes itself by the fact that the interior of the housing is securely sealed from the outside area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages, characteristics and details of the invention can be seen from the descriptions below, in which the invention is described with reference to the drawings. Thereby, the claims and characteristics for the device as per the invention and the process as per the invention mentioned in the description, individually or in any combination, can be essential for the invention. Shown below are: 
         FIG. 1  a schematic representation of a mobile device that is made as an ID-transmitter and serves as a keyless activation of a locking device of a motor vehicle, 
         FIG. 2  a possible design variant of an ID-transmitter as per  FIG. 1 , 
         FIG. 3  another alternative of the ID-transmitter as per  FIG. 1 , 
         FIG. 4  a schematic top view of a support as per  FIG. 2  or  FIG. 3  in which the key unit is inserted and 
         FIG. 5  a schematic representation of the sectional view as per  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a mobile device  10 , whereby the device  10  has a housing  11 , which comprises an upper part  11   a  and a lower part  11   b . The upper part  11   a  and the lower part  11   b  are housing shells that are fixed to one another. In the interior of the housing  11  there is a switching element  40 , which is shown exemplarily in  FIG. 2  and  FIG. 3 . This switching element  40  can be activated through a key unit  20 , in which the user presses on the key unit  20 , which will be further addressed below. The key unit  20  is formed out of a key element  22  and a support  23 , which is shown if  FIG. 2  and  FIG. 3 . The key element  22  surrounds the support  23 . Here, the edge of the key element  22  is slipped over the support  23 . In the present example of the version, the key element  23  has several individual keys  26 . 1 ,  26 . 2 ,  26 . 3 . 
     The key unit  20 , as per  FIG. 2  and  FIG. 3 , is provided with three contacting devices  21 , whereby each contacting device  23  is directed towards the interior  12  of the housing  11 . A deformation of the material of the key element  22  takes place if the user exerts a force on the key unit  20  or, in particular, on the any individual key  26 , whereby the contacting device  21  moves in the direction of the interior  12 . 
     The key unit  20  is set and fixed in a receptacle  13  of the housing  11 . Here, the receptacle  13  has a force transmission area  14  that runs between the key unit  20  and the switching elements  40  that are arranged in the interior  12  of the housing  11 . Here, the interior  12  of the housing  11  is completely sealed off from the outside area  2  of the mobile device  10 . The housing  11  and the force transmission area  14  form a combined, two-part structural unit, whereby the force transmission area  14  is made out of the first material and the housing  11  is made out of the second material, whereby the first material has a lower mechanical resistance than the second material. Here, the force transmission area has a soft component in its first material. The rest of the housing area on the other hand is designed harder. 
     As per  FIG. 4  and  FIG. 5 , the support  23  has several gaps  24 , through each of which a contacting device  21  projects. Here, a depression  25  is formed on the support  23  at each gap  24 . The depression  25  has a curved geometry, whereby, when the key element  22  is not operated, there is a space remaining in front of the curved area of the depression  25 . Now, if the key element  22  of any individual key  26  is operated, a deformation takes place so that the contacting device  21  moves in the direction of the force transmission area  14  or of the switching element  40 . A contacting of the individual key  26  with the curved area of the depression  25  takes place after a defined stroke length of the individual key  26 , which serves as a stop. Due to this, a further depressing of the individual key  26  is prevented, so that damage, particularly to the switching element  40 , can be ruled out. 
     As per  FIG. 2 , the flexible key element  20  is stretched over the support  23 . The significant difference in  FIG. 3  is that the support  23  at least has a protrusion  27  on its side, which projects through an opening of the key element  22 . Due to this, an additional fastening effect of the key element  20  to the support  23  can be achieved. 
     As per all versions of the invention, the key unit  20  is laser welded to the force transmission area  14  of the housing  11 . Here, the material of the force transmission area  14  is designed to be laser transparent. The parts to be welded together are therefore on the one hand the force transmission area  14  and on the other the support  23 . As per  FIG. 3 , the protrusion  27  of the support  23  is laser welded with the force transmission area  14 . 
     As  FIG. 2  and  FIG. 3  make clear, the receptacle  13  is made out as a depression in the housing  11 , in which the key unit  20  is located. Here the surface of the key unit  20  is arranged almost flush with the surface of the housing  11 . 
     As  FIG. 2  exemplarily shows, the force transmission area  14  can be made with various indentations  16 , which project in the direction of the support  23  or of the appropriate contacting device  21 . Switching elements  40  are located under the force transmission area  14 . Each switching element  40  is assigned to a particular individual key  26 . The switching elements  40  can be mechanical switches, electromechanical switches, etc. The switching elements  40  are arranged on a circuit board which is not illustrated (no reference number) in the interior  12  of the housing  11 . A signal can be triggered by activating the switching element  40 , by which in turn different functions are started, for example as per  FIG. 1 , a locking procedure or an unlocking procedure in a motor vehicle  1 . 
     As per  FIG. 1 , a haptic element  15  is provided between individual keys  26 , which is designed to be so different from the individual keys  26  in its material properties, that the user is exposed to satisfying tactile properties and tactile response of the individual keys  26 . In particular, the haptic element  15  causes the individual key  26  to return to its original position after a corresponding operation by the user. The individual keys  26  form a keypad, where the individual keys  26  and the haptic element  15  build a monolithic structural element which is fixed to the support  23  as per  FIG. 2  or  FIG. 3 . 
     During the assembly of the mobile device  10 , in an initial step the key element  10  is stretched onto the support  23 , which is made from at harder material than the key element  22 , so that the key element  22  is securely fastened to the support  23 . The fixing of the key element  22  onto the support  23  is done without adhesive. Finally, the key unit  20  is set into the receptacle  13 . The laser welding of the support  23 , particularly of the protrusion  27 , to the force transmission area  14  follows in the next step.