Patent Publication Number: US-2006003818-A1

Title: Hinge lock

Description:
FIELD OF THE INVENTION  
      The present invention relates to a telephone device and a hinge unit in a telephone device.  
     BACKGROUND  
      Communication devices have during the last decades evolved from being more or less primitive telephones, capable of conveying only narrow band analog signals such as voice conversations, into the multimedia mobile devices of today capable of conveying large amounts of data representing any kind of media. For example, a telephone in a GSM, GPRS, EDGE, UMTS or CDMA2000 type of system is capable of recording, conveying and displaying both still images and moving images, i.e. video streams, in addition to audio data such as speech or music.  
      Needless to say, such devices usually require one or more large display screens as well as at least one keypad with input means. Consequently, such devices are often of the folding type having a double housing, i.e. two housing parts joined together with hinge means.  
      One problem related to such telephones having two main housing parts joined together with, e.g., a tilt and swivel hinge, is that they may tend to be more fragile when subject to rough handling. It is hence important that the hinge is very robust and reliable. A mobile phone is exposed to various mechanical stresses and shocks from e.g. accidental drops and other rough handling. A hinge in a foldable mobile phone is further exposed to friction forces in connection with opening/closing of the phone, which can be many times a day. Still it is expected that the hinge of the phone work properly, during years of use.  
      At the same time it is necessary that the hinge provides for a user to open and close the foldable parts of the phone in an easy and comfortable manner. The friction in the hinge should not be to high, but has to be just high enough to keep the parts in the preferred open position. As it in general is desired to keep a the size and weight of the mobile phone as low as possible the hinge parts should be as small and light as possible. In order minimize production cost, the hinge parts should designed in order to facilitate automatic assembly.  
      Prior art hinges in general do not provide all of these necessary characteristics. For example, U.S. Pat. No. 6,148,480 and U.S. Pat. No. 6,633,643 disclose hinge constructions for telephones, without discussing any problems as those stated above.  
     SUMMARY OF THE INVENTION  
      It is hence an object of the present invention to provide a foldable telephone, which is capable of withstanding rough handling. That is, to provide a telephone with a hinge mechanism which does fulfill the above requirements for shock resistance while at the same time being easy to assemble and does not compromise the general requirements of mobile telephones.  
      The object is achieved by means of a telephone according to claim  1  and a hinge device according to claim  5 .  
      A telephone according to the invention comprises a first housing part and a second housing part, where the first and second housing parts are electrically and mechanically joined via a tilt and swivel hinge. The hinge is configured to allow movement of the first and second housing parts between a plurality of positions relative to each other, and the hinge comprises a tilt shaft and a swivel shaft arranged along a tilt axis and a swivel axis, respectively. The tilt shaft is arranged at least partly within the first housing part and the first housing part is configured to engage with a hinge lock device, which is configured to prevent the tilt shaft from moving relative to the first housing part along the tilt axis.  
      Preferably, the hinge lock device is a substantially flat C-type washer having a semi circular opening, straddling the tilt shaft and engaged with the tilt shaft via a tilt shaft hinge cap.  
      The washer comprises, in a preferred embodiment, a finger extending from the washer, where said finger is engaged with a pin extending from the first housing part of the telephone. The pin is preferably made of a material suitable for being melted for locking the washer to the first housing part of the telephone.  
      An advantage of the present invention is that a telephone nwith such a hinge mechanism solves the problems related to the requirements of shock proofness. Moreover, at the same time assembly is relatively easy and a telephone equipped with a hinge lock device does not compromise the general requirements of multimedia foldable telephones. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIGS. 1   a - 1   c  are schematically drawn perspective views of a telephone according to the present invention.  
       FIG. 2  is a functional block diagram of a telephone according to the present invention.  
       FIG. 3   a  is a perspective view from above of a hinge part of a telephone according to the present invention.  
       FIG. 3   b  is a perspective view from below of the hinge part depicted in  FIG. 3   a , showing more details than  FIG. 3   a.    
       FIGS. 4   a  and  4   b  are perspective views illustrating a hinge lock engaging with a hinge via a hinge cap. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      In the following a mobile telephone having multimedia communication capabilities will be used to exemplify the present invention. However, it is to be understood that any type of foldable telephone, with or without, e.g., a camera is equally representative.  
       FIGS. 1   a ,  1   b  and  1   c  are three different perspective views of a telephone  100  according to the present invention. The view in  FIG. 1   a  shows the telephone  100  with a first housing part  101  and a second housing part  103 . The first housing part  101  comprises a keyboard  105  and the second housing part  103  comprises a display  107 . A tilt and swivel hinge  109  connects the two housing parts  101 ,  103  together and in  FIG. 1   a  the two housing parts  101 ,  103  are in a position relative to each other where they are slightly tilted with respect to each other around a tilt axis  120 . A swivel axis  130 , around which the second housing part  103  can swivel, is also indicated in  FIG. 1   a . The situation illustrated in  FIG. 1   a  is one during which a user of the telephone  100  may manipulate and input information via the keyboard  105  while at the same time viewing output information on the display  107 .  
      The view in  FIGS. 1   b  and  1   c  show the two housing parts  101 ,  103  in positions relative to each other, which is different from the relative position shown in  FIG. 1   a . Moreover, a camera  111  is shown, which is comprised in the first housing part  101 . The second housing part  103 , with its display  107 , is in  FIG. 1   b  tilted around the tilt axis  120  and swiveled around the swivel axis  130 , thereby illustrating a first relative position between the housing parts  101 ,  103 . In  FIG. 1   c , the second housing part  103 , with its display  107 , is tilted around the tilt axis  120  and swiveled around the swivel axis  130 , thereby illustrating a second relative position between the housing parts  101 ,  103 .  
       FIG. 2  shows a block diagram of a telephone  200  according to the present invention. A first housing part  201  comprises a processing unit  210  connected to an antenna  222  via a transceiver  220 , a memory unit  212 , a microphone  214 , a keyboard  205 , a speaker  216  and a camera  218 . The processing unit  210  is also connected to a display  207 , which is comprised in a second housing part  203  of the telephone  200 .  
      No detailed description will be presented regarding the specific functions of the different blocks of the telephone  200 . In short, however, as the person skilled in the art will realize, the processing unit  210  controls the overall function of the functional blocks in that it is capable of receiving input from the keyboard  205 , audio information via the microphone  214 , images: via the camera  218  and receive suitably encoded and modulated data via the antenna  222  and transceiver  220 . The processing unit  210  is also capable of providing output in the form of sound via the speaker  216 , images via the display  207  and suitably encoded and modulated data via the transceiver  220  and antenna  222 .  
      The second housing part  203  is mechanically connected to the first housing part  201  via a tilt and swivel hinge  209 . The display  207  is electrically connected to the processing unit  210  via electric connection means (not shown in  FIG. 2 ) comprised in the hinge  209 .  
      It is to be noted that the different blocks that have been described above are functional blocks and do not necessarily correspond to actual hardware units in a one-to-one relationship. As the skilled person will realize, functionality comprised in the blocks of  FIG. 2  may, wholly or in part, be comprised in one or more integrated circuits in the form of any mixture of programmable and non-programmable circuits.  
      Turning now to  FIGS. 3   a ,  3   b ,  4   a  and  4   b  where a hinge assembly connecting a first housing part  301  and a second housing part  303  of a telephone  300  is shown from two different viewing directions.  FIG. 3   a  is more or less schematically drawn, while  FIG. 3   b  illustrates the hinge assembly in more detail.  
      The hinge assembly comprises a tilt shaft  309  and a swivel shaft  311  aligned, respectively, along a tilt axis  320  and a swivel axis  330 . The tilt shaft  309  is arranged substantially within a recess  313  of the first housing part  301  of the telephone  300 , whereas the second housing part  303  of the telephone  300  is attached to a middle section of the tilt shaft  309 , to which the swivel axis  311  is connected.  
      The recess  313  forms a part of the first housing part  301  and has circular openings  315  into which the tilt shaft  309  fits. The tilt shaft  309  is connected to the first housing part  301  via a respective hinge cap  317  (only one hinge cap  317  is shown in  FIGS. 3   a  and  3   b ).  
      In order to prevent the tilt shaft  309  from axial movements, due to rough handling such as being dropped from a height and being subject to a mechanical shock when hitting the ground, a hinge lock  340  is used. The hinge lock  340  is preferably in the form of a substantially flat C-type washer having circumference parts  323  defining a semi circular opening. A finger  321  with a hole  322  protrudes at an approximately right angle from the substantially flat washer  340 .  
      The hinge lock  340  is arranged in the recess  313  of the first housing part so that the half circular opening, as defined by the circumference parts  323 , fits into a recess  324  of the hinge cap  317 , which is fitted onto the tilt shaft  309 . Notches  325  in the hinge cap  31 . 7  engage with protrusions  326  of the first housing part  301  in order to secure the hinge cap  317  in the recess  313 . The hole  322  in the finger  321  is fitted onto a plastic pin  328  forming part of the first housing part  301 . The plastic pin  328  is preferably melted during the process of installing the hinge lock  340  and thereby rigidly securing the hinge lock  340  to the first housing part  301 . Thereby the tilt shaft  309  is prevented from axial movement and the hinge lock  340  is prevented from falling out of the first housing part  301 .