Abstract:
A battery charger for a portable radio having a cradle which holds and charges a radio with a battery attached, or optionally holds and charges the battery alone. The cradle is typically mounted in a vehicle. A lock element is provided in the cradle to engage the battery and is operated by a lock actuator and a release actuator. The lock actuator is displaced when the radio or battery is pushed into the cradle by a user. The release actuator may be displaced by the user to disengage the lock from the battery.

Description:
BACKGROUND TO THE INVENTION 
       [0001]    This invention relates to a battery charger for a portable radio, particularly a charger which is adapted for use in a vehicle. 
         [0002]    A wide range of chargers are available for hand portable radios, cell phones and other portable electronic devices. When designed for use in a vehicle they are typically also required to hold the device against sudden movements, and should provide the user with a convenient mechanism for locking and release. 
         [0003]    The chargers are often manufactured as a cradle which holds the device with battery attached, and connects the battery to a charging circuit which is powered from the vehicle. The user simply places the radio in the cradle to charge the battery. In the case of a portable radio, the charger may be able to hold a battery alone, for convenience in providing the user with a spare. 
         [0004]    In this specification the term “radio” generally refers to a radio including a battery, and the term “battery/radio” refers to the battery alone or when attached to the radio. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the invention to provide an improved battery charger for hand portable radios, or at least to provide an alternative to existing chargers. 
         [0006]    In one aspect the invention may be said to reside in a battery charger for a portable radio, having a cradle which receives the battery alone or attached to the radio. A lock actuator is provided in the cradle and is displaced when the battery/radio is pushed into the cradle by a user. A lock is also provided in the cradle to engage the battery/radio as the lock actuator is displaced. A release actuator is also provided and is displaced by the user to disengage the lock from the battery/radio for removal of the battery/radio from the cradle. 
         [0007]    Preferably the locking actuator includes a foot which is biased upwards in the cradle and onto which the base of the battery/radio is urged downwards by the user. The locking actuator also includes a portion which restrains the lock until the locking actuator is displaced by the base of the battery/radio. 
         [0008]    Preferably the locking latch is biased transversely in the cradle and is released to engage the battery/radio by downwards displacement of the locking actuator. In one embodiment the lock is formed by a pair of arms which engage recesses in the battery. In another embodiment the lock is formed by a pair of pins mounted separately in the cradle. 
         [0009]    Preferably the release actuator is biased upwards in the cradle and urges the locking latch transversely away from the battery/radio when pushed downwards by the user. The release actuator may also include a pair of cam surfaces which engage corresponding surfaces on the locking latch to urge the latch away from the battery/radio. 
         [0010]    The charger contains an electrical circuit and electrical contacts through which the battery can be charged. Fixtures may be included for mounting the cradle in a vehicle. 
     
    
     
       LIST OF FIGURES 
         [0011]    Preferred embodiments of the invention will be described with reference to the accompanying drawings, of which: 
           [0012]      FIG. 1  is a perspective view of a first embodiment of a charger for a hand portable radio, 
           [0013]      FIG. 2  is an exploded view showing main components of the first embodiment, 
           [0014]      FIGS. 3   a ,  b ,  c  are vertical sections through the charger in empty, radio locked and radio released configurations, 
           [0015]      FIGS. 4   a ,  b ,  c  are horizontal sections through the charger corresponding to  FIGS. 3   a ,  b ,  c , 
           [0016]      FIGS. 5   a ,  b  are vertical and horizontal sections showing the locked configuration with battery only, 
           [0017]      FIG. 6  is a vertical section showing electrical contacts in the radio locked configuration, 
           [0018]      FIG. 7  is an exploded view showing main components of a second embodiment of the charger, 
           [0019]      FIGS. 8   a ,  b ,  c  are vertical sections through the second charger in empty, radio locked and radio released configurations, and 
           [0020]      FIGS. 9   a ,  b ,  c  are horizontal sections through the second charger corresponding to  FIGS. 8   a ,  b ,  c.    
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    It will be appreciated that the invention may be implemented in a variety of ways for a range of different radios and batteries. The embodiments described here are given by way of example only. 
         [0022]      FIG. 1  shows a battery charger for the first embodiment of a hand portable radio, having a cradle formed by a lower portion  10  and an upper portion  11 . These portions are typically made from moulded plastic and fastened together by screws, although a range of options might be considered. The upper portion includes a recess  12  with a rim  13 , which receives the base of the radio, or the battery alone, and a rear support  14  which contains all or part of a lock and release mechanism for a rear part of the radio or battery. The lower portion forms a shell around part of the upper portion. 
         [0023]      FIG. 2  gives an exploded view of the cradle, showing a locking actuator  20 , a locking release actuator  21 , and locking latch  22 . In this example, the locking actuator and latch are in sliding contact with the release actuator which is in turn mounted in the upper portion of the cradle. A pair of spring loaded locking pins  23  are mounted in the rim  13 . These components form a lock and release mechanism which holds the radio or battery securely in the cradle. The components are typically made from plastic and may take a variety of shapes in other embodiments. 
         [0024]      FIGS. 3   a ,  b ,  c  and corresponding  FIGS. 4   a ,  b ,  c  indicate how the lock and release mechanism operates in relation to a complete radio  50  including battery  51 .  FIGS. 5   a ,  b  indicate how the lock and release mechanism operates in relation to the battery alone. 
         [0025]    The locking actuator  20  has an approximate L shape with a single leg  30 , and sits in a vertical orientation within the cradle, biased upwards by a spring  31 . A foot  32  on the lower end of the leg lies in the bottom of the upper portion  11  and extends into the recess  12 . An aperture  33  towards the upper end of the leg is guided by an internal part on the upper portion  11 . A shoulder  34  on the upper end of the leg is shaped to engage the locking latch  22 . 
         [0026]    The release actuator  21  has an approximately square O shape with a central aperture  35 , and sits in a vertical orientation in the upper portion of the cradle, biased upwards by a spring  36 . A contact portion  37  protrudes above the cradle. A pair of slots  39  guide the locking latch through the central aperture, and include respective cam surfaces  40 . A foot  41  is guided by an aperture in the upper portion  11  and rests on spring  36 . 
         [0027]    The locking latch  22  is approximately U shaped with a pair of arms  42  and lies in a horizontal orientation through the release actuator  21 , biased transversely by a spring  43 . The arms are able to slide in slots  39  on the release actuator while a pair of cam surfaces  44  are aligned with corresponding surfaces  40 . The ends of arms  42  are shaped to engage corresponding recesses in a battery. 
         [0028]      FIGS. 3   a  and  4   a  show the empty cradle. Locking actuator  20  is held upwards by spring  31 . Shoulder  34  on the locking actuator restrains the locking latch  22  in an open position, against spring  43 . The locking release actuator  21  is held upwards in an open position by spring  36 . All of the springs are seated on internal surfaces of the cradle as shown. 
         [0029]      FIGS. 3   b  and  4   b  show a radio  50  including battery  51  locked into the cradle by a user. Locking actuator  20  is displaced downwards in recess  12  against spring  31 , by contact of the battery on foot  32 . Locking latch  22  has been released by shoulder  34  and is displaced transversely into engagement with the battery by spring  43 . The radio generally abuts internal walls of the recess  12  and is biased firmly against arms  42  of the latch by spring  31 . Pins  23  have also engaged the battery but are not shown in this view. 
         [0030]      FIGS. 3   c  and  4   c  show how the radio  50  is released from the cradle. The user applies downwards pressure to contact portion  37  of the locking release  21 , against spring  36 . Cam surfaces  40  on the release actuator engage cam surfaces  44  on the locking latch  22  which restores the latch to the open position out of engagement with the battery  51 . The locking actuator and the radio are returned upwards by spring  31  and shoulder  34  again restrains the latch against spring  43 . 
         [0031]    The user then removes pressure from the release actuator which returns to the open position, and the radio can be removed from the cradle. 
         [0032]      FIGS. 5   a  and  5   b  correspond to  FIGS. 3   b  and  4   b , and show how the battery  51  is held in the cradle without necessarily being attached to the radio. The locking actuator, locking latch and release actuator behave as before. Pins  23  hold the battery in engagement arms  42  of the latch. Charging of a battery separately from the radio might be considered an optional feature. 
         [0033]      FIG. 6  is a sectional view indicating the location of electrical contacts  60  inside the cradle. These contacts meet corresponding contacts on the battery  51 . The associated electrical circuit and connection to an external power supply, typically a vehicle battery, will be known to a skilled reader and have not been shown. 
         [0034]    The cradle may be fixed within a vehicle in a variety of ways, depending on surfaces and fittings which are available inside vehicle. A range of brackets may be attached to the rear of the cradle for example. The cradle may also be held in an aperture having edges which are sandwiched between the upper and lower portions  10  and  11 . 
         [0035]      FIG. 7  shows a second embodiment of the battery charger, having a cradle formed by a lower portion  15  and an upper portion  16 . The upper portion includes a recess  17  with a rim  18 , which receives the base of the radio, or the battery alone, and a rear support  19  which contains all or part of a lock and release mechanism for a rear part of the radio or battery. 
         [0036]    The charger in  FIG. 7  includes a locking actuator  70 , a locking release actuator  71 , and a locking latch formed by a pair of pins  72  mounted separately in the upper portion  16 . The locking actuator and latch are in sliding contact with the release actuator which is in turn mounted in the upper portion of the cradle. These components form a lock and release mechanism which holds the radio or battery securely in the cradle. 
         [0037]      FIGS. 8   a ,  b ,  c  and corresponding  FIGS. 9   a ,  b ,  c  indicate how the lock and release mechanism operates in relation to a complete radio  50  including battery  53 . The lock and release mechanism may also operate in relation to the battery alone. 
         [0038]    The locking actuator  70  has an approximate L-shape with a single leg  80 , and sits in a vertical orientation within the cradle, biased upwards by a spring  81 . A foot  82  on the lower end of the leg lies in the bottom of the upper portion  16  and extends into the recess  17 . An aperture  83  towards the upper end of the leg is guided by an internal part on the upper portion  16 . A pair of arms  84  on the upper end of the leg are shaped to interact with the pins  72  of the locking latch. 
         [0039]    The release actuator  72  is an approximately square O-shape with a central aperture  85 , and sits in a vertical orientation in the upper portion of the cradle, biased upwards by a spring  86 . A contact portion  87  protrudes above the cradle. The arms of the locking latch are guided by internal sides of the central aperture  85 . Cam surfaces  90  on external sides of the central aperture interact with the pins  72 . A foot  81  is guided by an aperture in the upper portion  16  and rests on spring  86 . 
         [0040]    The locking latch is formed by a pair of separate latches or pins  72  in this example. Each pin has an approximate L-shape which includes a central block  91 , a cam surface  92  and a protrusion  93 . Each pin lies in a horizontal orientation biased transversely inwards to the cradle by a respective spring  94 . The cam surfaces  92  are aligned with corresponding cam surfaces  90  on the release actuator  71 . The protrusions  93  engage corresponding recesses in the battery  53 . 
         [0041]      FIGS. 8   a  and  9   a  show the empty cradle. Locking actuator  70  is held upwards by spring  81 . Arms  84  restrain the pins of locking latch  72  in an open position, against springs  94 . The locking release actuator  71  is held upwards in an open position by spring  86 . All of the springs are seated on internal surfaces of the cradle as shown. 
         [0042]      FIGS. 8   b  and  9   b  show a radio  50  including battery  53  locked into the cradle by a user. Locking actuator  70  is displaced downwards in recess  17  against spring  81 , by contact of the battery on foot  82 . Locking latch  72  has been released by arms  84  and the pins are displaced transversely into engagement with the battery by springs  94 . The radio generally abuts internal walls of the recess  17  and is biased firmly against the latch by spring  81 . Other pins provided in the cradle may also engage the battery but are not shown in this view. 
         [0043]      FIGS. 8   c  and  9   c  show how the radio  50  is released from the cradle. The user applies downwards pressure to contact portion  87  of the locking release  71 , against spring  86 . Cam surfaces  90  on the release actuator engage cam surfaces  92  on the locking latch  72  which restores the respective pins to the open position out of engagement with the battery  53 . The locking actuator and the radio are returned upwards by spring  81  and arms  84  again restrain the pins of latch  72  against springs  94 . 
         [0044]    The user then removes pressure from the release actuator  71  which returns to the open position, and the radio can be removed from the cradle.