Abstract:
A module unit is to be mounted to the exterior surface of a trunk door or rear door of a vehicle for displaying a license plate. Without requiring a key or special tool, the module unit protects the license plate from being removed by an un-authorized person. The license plate can only be removed when a locking unit in the module unit is unlocked by activating a release unit from the interior side of vehicle. Such a module unit also protects the annual registration stickers from being removed by an un-authorized person.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a holder assembly for retaining and displaying a vehicle license plate outside of a trunk door or rear door of a vehicle. The present invention particularly relates to a vehicle license plate holder that, without requiring a key or special tool, protects the license plate from being removed by an un-authorized person. 
   By law, a vehicle license plate must be displayed at least at the rear end of vehicle. Mechanical fasteners such as screws have always been used for fastening the plate to vehicle body. This presents a risk that the license plate can be removed by an un-authorized person. To prevent such a risk, a variety of lockable devices have been proposed in prior art that require a key or a special tool for removing the license plate. Using key or special tool is inconvenient and undesirable because the vehicle owner must maintain an extra key or special tool. This presents another risk of losing or missing the key or special tool when needed. Furthermore, most of the proposed lockable devices are unattractive in appearance. 
   Therefore, there is still a need for an improved license plate holder that, without requiring a key or special tool protects the vehicle license plate from being removed by an un-authorized person. The present invention suggests a locking and releasing units to be installed in the holder assembly. The releasing unit penetrates through the vehicle body of trunk door or rear door of the vehicle. To remove the license plate, the locking unit must be unlocked by activating the releasing unit from the interior side of vehicle. The present invention adopts such a novel strategy for protecting the license plate from being removed by an un-authorized person, which has never been disclosed in prior art. The present invention is also capable of protecting the annual registration stickers of the license plate from being removed by an un-authorized person. By law, such annual registration stickers must be displayed at the top right and left corners of the license plate. 
   SUMMARY OF THE INVENTION 
   An object of present invention is to provide a license plate holder that prevents the removal of the license plate by an un-authorized person. 
   Another object of present invention is to provide a license plate holder that prevents the removal of the annual registration stickers of the license plate by an un-authorized person. 
   Another object of present invention is to provide such a license plate holder that does not requires a key or special tool for the removal of the license plate. 
   Another object of present invention is to provide such a license plate holder that mainly comprises of integrally connected molded parts, and thus enables quick assembling of the holder. 
   Another object of present invention is to provide such a license plate holder that eliminates visible mechanical fasteners, and thus enhances the appearance of the holder. 
   Another object of present invention is to provide a rotating means that rotates the holder to a closed position to prevent the removal of the license plate by an un-authorized person. 
   Another object of present invention is to provide such a rotating means that rotates the holder to an open position to allow the removal of the license plate. 
   Another object of present invention is to provide a locking means that is normally at locked position when the holder is at the closed position. 
   Another object of present invention is to provide such a locking means that can be unlocked to allow the holder to rotate from the closed position to the open position. 
   Another object of present invention is to provide a releasing means for unlocking the locking means, which rotates the holder to the open position and enables the removal of the license plate. 
   Another object of present invention is to provide such a releasing means that can be solely activated for unlocking the locking means from the interior side of vehicle. 
   Another object of present invention is to provide such a rotating means, locking means and releasing means in inaccessible locations so that they can not be possibly tampered by an un-authorized person. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a rear perspective view of the frame unit in the first preferred embodiments of present invention. 
       FIG. 2  is an exploded view of the locking unit that is installed in the frame unit ( FIG. 1 ) of the first preferred embodiments of present invention. 
       FIG. 3  is a rear perspective view of the base unit in the first preferred embodiments of present invention. 
       FIG. 4  is an exploded view of the releasing unit that is installed in the base unit ( FIG. 3 ) of the first preferred embodiments of present invention. 
       FIG. 5  is a front perspective view of the module unit in the first preferred embodiments of present invention. 
       FIG. 6  is a rear perspective view of the frame unit in the second preferred embodiments of present invention. 
       FIG. 7  is a rear perspective view of the base unit in the second preferred embodiments of present invention. 
       FIG. 8  is a front perspective view of the module unit in the second preferred embodiments of present invention. 
       FIG. 9  is a rear perspective view of the cavity fabricated in a vehicle body for concealing the base unit of  FIG. 7 . 
       FIG. 10  is a rear perspective view of the cavity fabricated in a vehicle body for concealing the rearward extended portion of the base unit of  FIG. 3 . 
       FIG. 11  is a perspective view of a transparent cover plate for protecting a license plate and annual registration stickers. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The module unit of the license plate holder of present invention comprises of a pivotally connected stationary base unit and rotating frame unit. 
     FIG. 1  shows a rear view of the rotating frame unit  1  in the first preferred embodiments of present invention in a horizontal position, with the front of frame unit  1  facing downward. The frame unit  1  consists of a right side “L-channel” bar  2 , a left side “L-channel” bar  3 , a bottom side “L-channel” bar  4 , and a first and second rear side cross plates  5  and  6 , which are integrally connected to form an integral frame structure with a central cavity  7 , and a top slot opening  8 . A license plate (not shown) fits nicely within the central cavity  7  when the license plate is inserted into the central cavity  7  of frame unit  1  through top slot opening  8 . 
   The frame unit  1  is provided with a locking unit  9  at the rear side of first cross plate  5 .  FIG. 2  shows an exploded view of locking unit  9 , which comprises of a top plate  10 , a sliding plate  11 , and a pair of parallel sliding tracks  12 . Sliding tracks  12  are the integral molded parts of cross plate  5 . The bottom side of top plate  10  has a number of integral connectors  13 , which allow an easy and quick connection with sliding tracks  12  through the matching holes  14  at the top sides of sliding tracks  12 . The sliding plate  111  has a pair of integral “L-hooks”  15 , a left end projectile  16 , and a cavity  17 . The top face of projectile  16  is facing leftward with an approximately 45 degree downward slope. The top plate  10  has a pair of windows  18 . The locking unit  9  is assembled by placing a spring coil  19  within cavity  17 , and placing the sliding plate  11  within the space between sliding tracks  12 , with the right end of spring coil  19  being retained by an integral stop  20  of sliding tracks  12 . The top plate  10  is then quickly connected to the top sides of sliding tracks  12 , with “L-hooks”  15  of sliding plate  11  penetrating through windows  18  of top plate  10 . After the locking unit  9  being assembled, sliding plate  11  is retained at an extreme left position by spring  19 . The sliding plate  11  slides to an extreme right position when the top face of end projectile  16  being pushed downward by an external force. “L-hooks”  15  of locking unit  9  are positioned at locked and unlocked positions when sliding plate  11  is retained at extreme left and right positions respectively. Spring  19  causes sliding plate  11  to return from the extreme right position to the extreme left position upon releasing of the external force. It is understood that other types or forms of locking mechanism may also be suitable for use. It is not the intent of present invention to limit the type or form of the locking mechanism. Any deviation in the type or form of the locking unit is considered within the scope and spirit of present invention. 
     FIG. 3  show a rear view of the stationary base unit  21  in the first preferred embodiments of present invention in a vertical position. The base unit  21  consists of a vertical right side plate  22 , a vertical left side plate  23 , a horizontal top side plate  24 , and a first and second rear side cross plates  25  and  26 , which are integrally connected in the form of an integral frame structure with a central cavity  27 . The cross plate  25  is divided into four sections, i.e., a right section  28 , a right mid section  29 , a left mid section  30 , and a left section  31 . The right mid section  29  is extended rearward with a pair of windows  32 . The left mid section  30  is extended further rearward that incorporates a releasing unit  33 . With an exception of the right and left mid sections  29  and  30  of cross plate  25 , the rear sides of the entire frame structure of base unit  21  are flush to the exterior surface of the vehicle body when base unit  21  is attached to the vehicle body. Since the right and left mid sections  29  and  30  of cross plate  25  are extended rearward, a cavity must be prefabricated in the vehicle body to conceal them before base unit  21  can be attached to vehicle body. 
     FIG. 4  shows an exploded view of releasing unit  33 . The releasing unit  33  consists of a cylindrical bearing  34 , a connecting rod  35 , a projectile  36 , a push button  37  and a spring  38 . The cylindrical bearing  34  that penetrates through left mid section  30  of cross plate  25 , is integrally connected to the rear side of cross plate  25 . The connecting rod  35  is capable of sliding within cylindrical bearing  34 , which is integrally connected with projectile  36  at the front end. The top face of projectile  36  has an approximately 45 degree slope. The releasing unit  33  is assembled by inserting connecting rod  35  into cylindrical bearing  34 , placing spring  38  into a cavity  39  at the rear end of cylindrical bearing  34 , and screwing the push button  37  onto the rear end of connecting rod  35 . The connecting rod  35  is normally retained at an extreme rear position by spring  38 . The connecting rods  35  slides forward to an extreme front position when push button  37  being pushed forward by an external force. Spring  38  enables connecting rod  35  to return to the extreme rear position upon releasing of the external force. It is understood that other types or forms of releasing mechanism may also be suitable for use. It is not the intent of present invention to limit the type or form of the releasing unit or locking unit. Any deviation in the type of form of the releasing or locking unit is considered within the scope and spirit of present invention. 
   The frame unit  1  and base unit  21  are pivotally connected together as a module unit by a pair of rotational joints. The female part of the rotational joint is in the form of a sleeve bearing  40  with a slot opening  41 , which is an integral part of bottom “L-channel” bar  4  of frame unit  1 . The male part of the rotational joint is in the form of a bracket  42  with a cross bar  43 , which is an integral part of cross plate  26  of base unit  21 . It is understood that other types or forms of rotational joints may also be suitable for use. It is not the intent of present invention to limit the type or form of the rotational joint. A deviation in the type or form of the rotational joint is considered within the scope and spirit of present invention. 
   The frame unit  1  and base unit  21  are positioned at horizontal and vertical positions respectively ( FIG. 1  and  FIG. 3 ) when they are pivotally connected. The rotational joint is connected by engaging cross bar  43  into sleeve bearing  40  through slot opening  41 , in which, cross bar  43  serves as the center axis of rotation. After the rotational joints being connected, frame unit  1  is rotated clockwise from the horizontal position to the vertical position. At the vertical position, frame unit  1  fits nicely within cavity  27  of base unit  21 . Wherein, “L-hooks”  15  of locking unit  9  penetrate through windows  32  of cross plate  25  of base unit  21 , and thus enables the locking unit  9  to be engaged into the locked position. This results in locking frame unit  1  at the vertical position within base unit  21 . When frame unit  1  is locked at the vertical position, the slot opening  8  of frame unit  1  is blocked by top plate  24  of base unit  21  so that license plate can not be possibly removed out of frame unit  1  through slot opening  8 . 
   After locking frame unit  1  at the vertical position within base unit  21 , the pivotally connected module unit can be mounted to vehicle body by fastening base unit  21  to vehicle body with mechanical fasteners. Through holes  44  are provided in frame unit  1  that allow mechanical fasteners to access the fastening holes  45  of base unit  21  for fastening base unit  21  to vehicle body. 
   After the module unit being mounted to vehicle body, frame unit  1  can be rotated counter clockwise from the vertical position to an incline position. A node  46  is provided at the outer surface of the sleeve bearing  40  of the rotational joint. Node  46  makes contact with vehicle body and stops the rotation of frame unit  1  when frame unit  1  reaches the incline position (i.e., say 45 degree). At such an incline position (i.e., say 45 degree), license plate can be inserted into or removed out of frame unit  1  through slot opening  8 , but can not possibly slip out of frame unit  1 . Since frame unit  1  can not possibly rotate 90 degree from the vertical position to the horizontal position (i.e., position for engaging or disengaging the rotational joint), the rotational joints can not possibly be disconnected after the module unit being mounted to vehicle body. 
   It is understood that a cavity and a through hole must be prefabricated in the vehicle body before mounting the module unit to vehicle body. The cavity provides a space to conceal the rearward extended right and left mid sections  29  and  30  of cross plate  25  of base unit  21 . The through hole allows cylindrical bearing  34  of releasing unit  33  to penetrate through vehicle body. A rubber seal around the through hole is recommended to ensure a water-tight penetration of vehicle body. 
   The frame unit  1  is releasable from the vertical locked position to the incline position (i.e. say 45 degree) by activating the releasing unit  33 . The releasing unit  33  ( FIG. 4 ) can only be activated by pushing the push button  37  that is located in the interior side of vehicle. Upon activating the releasing unit  33  by pushing the push button  37 , the top face of projectile  36  of the releasing unit  33  begins to engage with the top face of projectile  16  of the locking unit  9 . Consequently, “L-hooks”  15  of locking unit  9  is moved to the extreme right position (i.e., unlocked position) as soon as projectiles  36  and  16  being completely engaged. As a result, frame unit  1  is released from the vertical locked position to the inclined position. When frame unit  1  is at the incline position (i.e. say 45 degree), the top slot opening  8  of frame unit  1  is no longer blocked by top side plate  24  of the base unit  21 . This allows license plate be removed out of or inserted into frame unit  1 . 
     FIG. 5  shows a perspective front view of the module unit in the first preferred embodiments of present invention at vertical position, in which, a license plate is retained within frame unit  1  at vertical position. The front sides of the frame structure of frame unit  1  are flush with the front sides of the frame structure of base unit  21 . It is understood that a cavity and a through hole must be prefabricated in the vehicle body before mounting the module unit to vehicle body. The cavity provides a space to conceal the rearward extended right and left mid sections  29  and  30  of cross plate  25  of base unit  21  ( FIG. 3 ). The through hole allows cylindrical bearing  34  of releasing unit  33  ( FIG. 4 ) to penetrate through vehicle body. After the module unit being mounted to vehicle body, the rear sides of the right, left and top side plates  22 ,  23  and  24  of base unit  21  are flush with the exterior surface of the vehicle body. It can be noticed in  FIG. 5  that there are no visible mechanical fasteners, rotational joints, locking unit or releasing unit shown in the front appearance of the module unit. This dramatically enhances the appearance of the module unit. 
     FIG. 6  shows a rear perspective view of the rotating frame unit  47  in the second preferred embodiments of present invention in a horizontal position, with the front of frame unit  47  facing downward. The frame unit  47  is identical to frame unit  1  of the first preferred embodiments shown in  FIG. 1 , with an exception that frame unit  47  incorporates a pair of new rotational joints. The new rotational joint is in the form of a sleeve bearing  48  that is integrally connected to the bottom of frame unit  47 . The frame unit  47  incorporates a locking unit  49  that is identical to locking unit  9  in the first preferred embodiments of present invention. 
     FIG. 7  shows a rear perspective view of the stationary base unit  50  in the second preferred embodiments of present invention in a vertical position. The base unit  50  consists of a vertical left side plate  51 , a vertical right side plate  52 , a horizontal top side plate  53 , and a first and second rear side cross plates  54  and  55 , which are integrally connected in the form of an integral frame structure with a central cavity  56 . The cross plate  54  is divided into four sections, i.e., a right section  57 , a right mid section  58 , a left mid section  59 , and a left section  60 . A vertical partition wall  61  is provided between left mid section  59  and left section  60 . The right mid section  58  is extended forward with a pair of windows  62 . The left mid section  59  incorporates a releasing unit  63  that is identical to the releasing unit  33  in the first preferred embodiments of present invention. With an exception of the right mid section  58 , the rear sides of the entire frame structure of base unit  50  are flush to the exterior surface of the vehicle body when base unit  50  is attached to the vehicle body. A pair of sleeve bearings  64  are provided within base unit  50 . 
   Frame unit  47  ( FIG. 6 ) and base unit  50  ( FIG. 7 ) are pivotally connected together to form a module unit by inserting a bolt (not shown) through the center holes of sleeve bearings  48  and  64 . After the module unit being pivotally connected, frame unit  47  can rotate clockwise from the horizontal position to the vertical position. Wherein, locking unit  49  of frame unit  47  locks frame unit  47  at vertical position in the same manner as the first preferred embodiments. Frame unit  47  can rotate counter clockwise from the vertical position to an incline position. Preferably, the incline position of frame unit  47  is restricted by installing a stop pin (not shown) in the base unit  50 . At such a restricted incline position (i.e. say 45 degree), license plate can be manually inserted into or removed out of frame unit  47 , but can not possibly slip out of frame unit  47 . 
     FIG. 8  shows a perspective front view of the module unit in the second preferred embodiments of present invention at vertical position, in which, a license plate is retained within frame unit  47  at vertical position. The front sides of the frame structure of frame unit  47  are flush with the front sides of the frame structure of base unit  50 . The module unit of the second preferred embodiments can be mounted to vehicle body in two methods. In the first method, a cavity and a through hole is prefabricated in the vehicle body. The through hole allows releasing unit  63  to penetrate vehicle body. The cavity is in a size substantially equivalent to that of base unit  50 . When the module unit is mounted to vehicle body, the entire frame structure of base unit  50  is concealed within the cavity so that, preferably, the front sides of the vertical side plates  51  and  52 , and the front side of horizontal top plate  53  of base unit  50  are flush with the exterior surface of vehicle body surrounding the cavity. In the second method, only a through hole is prefabricated in the vehicle body. The through hole allows releasing unit  63  to penetrate vehicle body. The module unit is directly mounted to the exterior surface of vehicle body so that the rear sides of plates  51 ,  52  and  53  of base unit  50  are flush with the exterior surface of vehicle body. 
     FIG. 9  shows a rear perspective view of the cavity  65  and the through hole  66  fabricated in the vehicle body  67 . Cavity  65  is extended outward from the interior surface  68  of vehicle body  67 . The entire base unit  50  (in  FIG. 7 ) fits nicely within the space enclosed by cavity  65 , and is fastened to the exterior surface  69  of vehicle body  67  by fitting mechanical fasteners into the fastening holes  70 . Through hole  66  provides a passage for the cylindrical bearing  34  of the releasing unit  63  (in  FIG. 4 ) penetrating vehicle body  67 . 
     FIG. 10  shows a rear perspective view of the cavity  71  and the through hole  72  fabricated in the vehicle body  73 . Cavity  71  is extended outward from the interior surface  74  of vehicle body  73 . The rearward extended portion of base unit  21  (in  FIG. 3 ) fits nicely within the space enclosed by cavity  71 , and base unit  21  is fastened to the exterior surface  75  of vehicle body  73  by fitting mechanical fasteners into the fastening holes  76 . Through hole  72  provides a passage for the cylindrical bearing  34  of the releasing unit  63  (in  FIG. 4 ) penetrating vehicle body  73 . 
   The module unit in the above first or second preferred embodiments protects the license plate from being removed by an un-authorized person when the frame unit retains and displays the license plate at a vertical position. Such a module unit can be further modified so that it not only protects the license plate, but also protects the annual registration stickers of the license plate from being removed by an un-authorized person. By law, annual registration stickers must be displayed at the top right and left corners of the license plate. The module unit in the above first or second preferred embodiments can be modified by installing a transparent cover sheet at the front of the frame unit. The transparent cover sheet can be in a full size of license plate, or in a reduced size just to cover the top right and left corners of the license plate. 
     FIG. 11  shows a perspective view of a transparent cover plate  77 . The transparent cover plate  77  is in an equivalent size and shape of a license plate  78 . The transparent cover plate  77  is placed against the front surface  79  of license plate  78  when both the transparent cover plate  77  and the license plate  78  are inserted into the frame unit of present invention (in  FIG. 1  or  FIG. 3 ). Therefore, the annual stickers  80  are protected by the transparent cover plate  77  without a possibility of being removed when license plate  78  is retained by the module unit of present invention at locked vertical display position. As a result, the annual registration stickers can only be removed from or attached to license plate when license plate is removed out of the frame unit. It is understood that it is not the intend of present invention to describe all possible configurations of the module unit. For example, slot opening of frame unit and rotational joints in the above first or second preferred embodiments can be alternatively located at the opposite sides of frame unit so that frame unit rotates horizontally around a vertical axis. For another example, the first and second rear side cross plates of frame unit or base unit can be alternatively combined into a large rear side plate. Therefore, a modification or deviation in the configuration of the module unit as described in the above first or second preferred embodiments is considered within the scope and spirit of present invention.