Abstract:
A housing assembly for an electronic apparatus and in particular a mobile telephone is disclosed. The assembly includes two housing portions ( 21,23 ) for connection to each other and a release member ( 34 ) positionable between said portions ( 21,23 ), the release member ( 34 ) having a cam surface ( 38 ) thereon such that rotation of the release member ( 34 ) urges said housing portions ( 21,23 ) apart.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a housing assembly for an electronic apparatus and, in particular, to a housing assembly for a mobile telephone.  
         BACKGROUND OF THE INVENTION  
         [0002]    A conventional mobile telephone generally comprises a housing including a front and a rear casing that are attached to each other using screws. Alternatively, one part may have integrally moulded clips that co-operate with corresponding recesses in the other part to hold them together. In addition, one part of the housing may also include a cover attached to its outer surface which, together with a recess in the housing, forms an acoustic duct for the transmission of sound from a transducer mounted in the housing to the outside. The cover also serves to conceal the screw holding the front and rear casing together and/or the RF test point.  
           [0003]    The cover also enables the telephone manufacturer to mark the product with the required logo or trademark depending on where or by whom the telephone is being sold, without having to replace the entire front and/or rear casing which would be more expensive to manufacture with the desired logo or trademark embossed on it. In addition, more style conscious people wish to personalise their telephones and the cover can be replaced with one of a different colour much more easily than part of the casing itself.  
           [0004]    The cover is attached to a conventional mobile telephone using adhesive, for example, double sided adhesive tape, or resilient clips moulded integrally with the cover that engage in corresponding recesses in the casing. It will be apparent that it is often desirable to remove the cover to obtain access to the region of the casing beneath it, or to replace it. However, the cover is difficult to remove and this is normally achieved by inserting a tool such as a screwdriver or other thin blade between the cover and the casing to which it is attached. Once the tool has been inserted between the two components, the cover is then levered off the casing. A disadvantage with this arrangement is that the casing can be easily damaged or, at the very least, badly scratched so that it must also be replaced.  
         SUMMARY OF THE INVENTION  
         [0005]    According to one object of the present invention, there is provided a housing assembly for an electronic apparatus including first and second housing portions for connection to each other and a release member positionable in a recess in the first housing portion, said release member including a cam that protrudes from the recess on rotation of the release member to engage the second housing portion and separate the second housing portion from the first housing portion.  
           [0006]    In a preferred embodiment, the cam is configured so that progressively more of it protrudes from the recess as the release member is rotated.  
           [0007]    Preferably, the release member includes an attachment for releasably mounting it to the first housing portion, the first housing portion including an aperture to receive the attachment on the release member.  
           [0008]    The attachment preferably comprises a lug on the release member, the aperture in the first housing portion being shaped to receive the lug, the lug engaging the first housing portion to mount the release member thereto on rotation of the release member after insertion of the lug through the opening.  
           [0009]    Preferably, the cam protrudes from the recess to force the first and second housing portions apart when the release member is rotated back to the orientation in which it was inserted.  
           [0010]    In a preferred embodiment, the opening is located in the base of the recess.  
           [0011]    A resilient compressible washer is advantageously located in the recess against the base and, most preferably, the underside of the base includes a plurality of dimples thereon, the lugs passing over the dimples when the release member is rotated to releasably mount it to the first housing portion.  
           [0012]    In a preferred embodiment the release member is configured such that the lugs clear the dimples when the release member is pushed downwardy to compress the washer before rotating the release member to attach it to the first housing portion, the resilience of the washer biasing the lugs into contact with the base when the force is removed, the dimples preventing further rotation of the release member.  
           [0013]    Conveniently, the cam is a flange on the release member having an angled cam surface for engagement with the second housing portion on rotation of the release member.  
           [0014]    The cam surface is preferably annular and the release member includes a cylindrical portion extending from the flange.  
           [0015]    In one embodiment, an aperture is formed in the cover, the diameter of the aperture being substantially equal to the diameter of the cylindrical portion so that the cylindrical portion is received in the aperture when the second housing portion is placed over the first housing portion and the cam surface.  
           [0016]    A boss conveniently protrudes from the cylindrical portion of the release member and has an aperture therethrough to receive a wrist strap.  
           [0017]    In the most preferable embodiment, the housing assembly comprises a mobile telephone.  
           [0018]    According to another object of the invention, there is also provided a method of separating two housing portions in a housing assembly according to the invention, comprising the steps of rotating the release member such that the cam means protrudes from the recess and lifts the second housing portion from the first housing portion.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a schematic illustration of a preferred embodiment of the invention in which the electronic device is a mobile telephone;  
         [0020]    [0020]FIG. 2 illustrates the main components of the telephone shown in FIG. 1 for connection to a cellular or cordless telephone network;  
         [0021]    [0021]FIG. 3 illustrates a rear view of the telephone shown in FIG. 1 with the cover removed;  
         [0022]    [0022]FIG. 4 illustrates a partial enlarged view of the rear of the telephone shown in FIG. 3 with the cover in place;  
         [0023]    [0023]FIG. 5 illustrates a perspective view of the release member incorporating a wrist strap fixing loop;  
         [0024]    [0024]FIG. 6 illustrates a partial enlarged perspective view of the rear of the telephone shown in FIG. 3;  
         [0025]    [0025]FIG. 7 illustrates a partial enlarged perspective view of the other side of the rear of the telephone casing shown in FIG. 3 and in FIG. 6;  
         [0026]    [0026]FIG. 8 illustrates a partial enlarged perspective view of rear of the telephone casing shown in FIG. 7, but with the release member shown in its locked position; and  
         [0027]    [0027]FIG. 9 illustrates a partial enlarged sectional view through the casing showing the release member in its locked position therein. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    An embodiment of the invention will now be described, by way of example only, with reference to the drawings described above.  
         [0029]    A preferred embodiment of the electronic apparatus according to the invention is a mobile telephone  1  as illustrated in FIG. 1. The telephone comprises a user interface having a keypad  2 , a display  3 , an on/off button  4 , ear piece  5  and a microphone  6 . The telephone is adapted for communication via a wireless telecommunication network, e.g. a cellular network. However, the telephone could also have been designed for a cordless network. The keypad  2  has a first group of keys  7  which are alphanumeric and by means of which a user can enter a telephone number, write a text message (SMS), write a name associated with a telephone number, etc. Each of the twelve alphanumeric keys  7  is provided with a figure “0-9” or a sign “#” or “*”, respectively. In alpha mode, each key  7  is associated with a number of letters and special signs used in text editing.  
         [0030]    The keypad  2  additionally comprises two soft keys  8 , the functionality of which depends on the state of the telephone and the navigation in the menu by means of a navigation key  10 , and two call handling keys  9 , which can be used for establishing a call or a conference call, terminating a call or rejecting an incoming call.  
         [0031]    [0031]FIG. 2 illustrates the main parts of the telephone  1  which is adapted for use in connection with a GSM network or any other telephone network. The telephone  1  may also configured to meet the wireless application protocol specification (WAP) agreed by most of the major telephone manufacturers and service providers that enables the telephone  1  to be used to access the internet. The microphone  6  produces analog electric signals corresponding to the user&#39;s speech and the analog signals are A/D converted in an A/D converter in the audio part  14 . The digital speech signals are further encoded in the audio part  14  and transferred to a controller or processor  18  which forms an interface between peripheral components of the device, including a RAM memory  17   a  and a Flash ROM memory  17   b , a SIM card  16 , the display  3  and the keypad  2 . The controller  18  communicates with a transmitter/receiver circuit  19 . The audio part  14  also decodes digital speech signals which are transferred from the controller  18  to the speaker  5 , via a D/A converter. The controller  18  is also connected to the keypad  2  and monitors the status of the telephone  1 . If the status of the telephone  1  changes in response to, for example, a user activating a button on the keypad  2 , the change is detected by the controller  18  and an indication of the change is shown on the display  3 .  
         [0032]    The telephone  1  has a housing formed from three main components, a front casing  20 , a rear casing  21  and a cover  23 . The rear casing includes an integrally moulded cylindrical portion  22  through which the antenna of the telephone may extend. As shown in FIGS. 3 and 4, the cover  23  is attached to a portion of the upper region  26  of the rear casing  21  which also has a battery chamber  24  to which a battery (not shown) together with a battery chamber cover may be attached. The battery chamber cover includes means by which it co-operates with the rear casing  21  using the integrally moulded clips  25  and the detent  27  on the casing  21  so as to releasably attach it thereto.  
         [0033]    The portion  26  of the upper region of the casing over which the cover  23  is fitted is raised or slightly outwardly bulbous in shape and the cover  23  is correspondingly shaped to fit over the portion  26  so that the underside of the cover  23  is in contact with the casing  21  when fitted thereto in the direction of arrow X in FIG. 3. As is shown in FIG. 3, the portion  26  of the casing  21  in the region of the cover  23  has an aperture  28  therethrough for the transmission of sound through the casing  21  from a transducer (not shown) mounted on the other side of the casing  21  over the aperture  28 . A depression or recess  29  extends across the portion  26  and, together with the cover  23 , forms an acoustic duct for the transmission of sound to the outside via narrow openings  30  where the cover and the casing meet in the region of the recess  29 . An opening  30 a in the casing  21  in the portion  26  is also provided to enable access to be obtained to the RF test point when the cover  23  is removed. Additionally, holes for the passage of screws for attaching the front and rear casings  20 ,  21  together may also be provided in the portion  26  beneath the cover  23  so that they are concealed from view for aesthetic reasons when the cover  26  is in place, although for clarity no screw holes are visible in the accompanying drawings.  
         [0034]    The cover  23  may be clipped to the casing  21 . However, in the present embodiment no clips are shown and the cover  23  is attached to the casing  21  using adhesive. The edge  31  of the portion  26  of the casing  21  may be lower than the surface of the casing  21  to define a shoulder against which the cover  23  locates so that the edge of cover  23  is flush with the casing  21  when attached thereto.  
         [0035]    A circular recessed area  32  in the portion  26  of the casing  21  is visible in FIG. 3 and receives a release member  34  (omitted from FIG. 3 but shown in FIG. 4 and  5 ), that protrudes through an aperture  33  in the cover  23  located directly above the recessed area  32 . The release member  34  and the recessed area  32  of the casing  21  will now be explained with reference, in particular, to FIGS.  5  to  9 .  
         [0036]    The release member  34  is shown in FIG. 5 and comprises a shaft portion  35  having a pair of diametrically opposite locking lugs  36  extending perpendicularly therefrom at its lower end. The other end of the shaft  35  is provided with a circular flange  37  which reduces in thickness from a maximum height H to a minimum height h as shown in the Figure. The overall diameter of this flange  37  is equal to, or slightly less than, the diameter of the recess  32  in the casing  21 . The upper surface of the flange  37  defines an angled cam surface  38  and its function will be explained in more detail later. A cylindrical portion  39  extends from the flange  37  and its walls define a shoulder  40  on the flange  37  having a height substantially equal to the thickness of the cover  23 . The angled cam surface is annular in shape. The overall diameter of the cylindrical portion  39  is equal to, or slightly less than the diameter of the aperture  33  in the cover. An elliptical boss  41  upstands from the upper surface of the cylindrical portion  39  an has an aperture  42  therethrough.  
         [0037]    Referring now to FIG. 6, the circular recessed area  32  in the casing  21  can be seen in more detail. Due to the outwardly bulbous shape of the portion  26  of the casing  21 , the depth of the recess increases from a minimum depth nearest to the edge of the casing to a maximum depth near to the region in which the transducer is mounted to the casing. The maximum and minimum depths of the recess are substantially equal to the heights H and h of the flange  37  of the release member described above, and this can be most clearly seen in the sectional view of FIG. 9.  
         [0038]    The base  44  of the recess  32  has an opening  45  comprising a part circular portion  45   a  in the centre of the recess and two elongate openings  45   b  extending from the part circular portion. A resilient rubber washer  43  is disposed in the recess  32  for reasons that will become apparent and has an identical opening to that of the base  44  of the recess  32 .  
         [0039]    The other side of the casing  21  is shown in FIG. 7, and the recess  32  is visible as a boss  46  on this side of the casing. The other side of the base  44  of the recess  32  has four raised dimples or pips  47  formed thereon.  
         [0040]    The release member  34  is attached to the casing  21  in the following manner. The release member  34  is oriented so that the shaft  35  passes through the part circular portion  45   a  in the opening  45  in the centre of the recess  32  and each lug  36  passes through one of the elongate portions  45   b  extending from the part circular portion  45   a . The release member  34  is then rotated 90 degrees to the position shown in FIGS. 8 and 9 so that the lugs  36  engage with the base  44  of the recess  32  and removal of the release member  34  from the recess  32  is prevented. To positively retain the release member  34  in its rotated or locked position, it must be pushed downwardly against the rubber washer  43  to compress it before the lugs  36  clear the base  44  of the recess  32  so that the release member  34  can be rotated . As it is rotated, the lugs  36  must ride over the pips  47 , further compressing the washer  43  before seating between them. It will therefore be appreciated that the release member  34  can only be rotated back to its insertion position once downward pressure has been applied to it sufficient to compress the washer  43  so that the lugs  36  can pass back over the pips  47 .  
         [0041]    Once the release member  34  has been locked in position as described above, the cover  23  is then glued in position on the portion  26 . The underside of the cover  23  seats against the cam surface  38  of the flange  37  and the walls of the aperture  33  in the cover  23  seat against the shoulder  40  of the cylindrical portion  39 , so that only the upper surface of the cylindrical portion and the boss  41  are visible once the cover  23  is in place, as can be most clearly seen in FIGS. 4 and 9.  
         [0042]    The aperture  42  in the boss  41  is provided to enable a wrist strap (not shown) to be connected to the release member  34  to enable the telephone  1  to be carried more easily. However, it will be appreciated that this is only a preferred embodiment and the boss  41  need not have an aperture  42  therethrough. In another embodiment, the boss  41  may be removed altogether and, the upper surface of the cylindrical portion  39  may be provided with a slot to enable rotation of the release member  34  using a tool such as a screw driver or a coin or such like.  
         [0043]    When the cover  23  is to be separated from the casing  21 , the release member  34  is rotated back to the orientation in which it was inserted. To rotate it, a downward pressure must be applied to compress the washer  43  so that the lugs  36  will freely pass over the pips  47 , as previously explained. As the release member  34  is rotated, the cam surface  38  which, with the release member  34  in its locked position, is usually flush with or lower than the surface of the region  26  of the casing  21 , is forced against the underside of the cover  23 , urging it away from the casing  21  and breaking the adhesive or other connection holding the two components together. The cover  23  can then be easily peeled off the casing  21 .  
         [0044]    It will be appreciated that as the separating force is applied directly to the underside of the cover  23  by the cam surface  38  as the release member  34  is rotated, the cover  23  can be easily separated from the casing  21  to obtain access to the portion  26  beneath the cover  23  or to replace the cover  23  with a new one, without causing any damage to either the cover  23  or the casing  21 .