Abstract:
An electricity-operated window blind is constructed to include a headrail, a driving mechanism mounted inside the headrail and having a power input device for rotation upon receipt of power supply, and a power output device for synchronously rotating with the power input device, a bind body suspended below the headrail and coupled to the power output device and controlled by the power output device to change window shading status, and a control mechanism. The control mechanism includes a suspension rod downwardly suspended from the headrail by a first end thereof, and a controller installed in a second end of the suspension rod. The controller has a battery set electrically coupled to the power input device for providing the necessary working power to the power input device.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to a window blind and, more specifically, to an electricity-operated window blind, which enables the user to replace the battery set conveniently and safely. 
   2. Description of the Related Art 
   A conventional electric window blind is generally comprised of a headrail fixedly located on the top side of the window, a blind body (slat assembly or curtain) suspended below the headrail, a motor drive mounted inside the headrail and coupled to the blind body, and a battery set installed in the headrail to provide the necessary working power to the motor drive, for enabling the motor drive to roll up or let off the blind down and to further change the window shading status. 
   Because the blind body is frequently opened and closed, the battery power of the battery set will be used up quickly. Further, due to limited space in the headrail, the sizes of the motor drive and the battery set (the output power of the motor drive and the storage volume of the battery set) are limited. Therefore, the battery set must be replaced with a new one when power low. However, because the battery set is installed in the headrail, which is located on the top side of the window (at a high place above the floor), the user may be not accessible to the battery set when standing on the floor. Therefore, when replacing the battery set, the user may need to use a ladder or stand means. However, it is dangerous to stand on a raised place when replacing the battery set, and the user may fall to the ground accidentally 
   SUMMARY OF THE INVENTION 
   The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an electricity-operated window blind, which enables the user to replace the battery set conveniently. 
   It is another object of the present invention to provide an electricity-operated window blind, which reduces the chance of the occurrence of an accident during replacement of the battery set. 
   To achieve these objects of the present invention, the electricity-operated window blind comprises a headrail, a driving mechanism mounted inside the headrail, a bind body suspended below the headrail, and a controller. The driving mechanism comprises a power input device for rotation upon receipt of power supply, and a power output device for synchronously rotating with the power input device. The bind body is coupled to the power output device and controlled by the power output device to change window shading status. The control mechanism comprises a suspension rod downwardly suspended from the headrail by a first end thereof, and a controller installed in a second end of the suspension rod. The controller has a battery set electrically coupled to the power input device for providing the necessary working power to the power input device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic drawing showing the basic structural arrangement of an electricity-operated window blind according to the first preferred embodiment of the present invention. 
       FIG. 2  is an exploded view in an enlarged scale of a part of the electricity-operated window blind shown in FIG.  1 . 
       FIG. 3  is a schematic drawing showing the basic structural arrangement of an electricity-operated window blind according to the second preferred embodiment of the present invention. 
       FIG. 4  is an exploded view in an enlarged scale of a part of the electricity-operated window blind shown in FIG.  3 . 
       FIG. 5  is a schematic partial view in section of an electricity-operated window blind according to the third preferred embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1 and 2 , an electricity-operated window blind  100  in accordance with the first preferred embodiment of the present invention is shown comprised of a headrail  10 , a blind body  20 , a driving mechanism  30 , and a control mechanism  40 . 
   The headrail  10  is transversely (horizontally) affixed to the top side of the window (not shown), having an inside space of suitable volume. 
   The driving mechanism  30  comprises a motor drive  31 . The motor drive  31  is comprised of a reversible motor  32  and an axle  33  coupled to the reversible motor  32 . The reversible motor  32  is fixedly mounted in the inside space of the headrail  10  at the right side. The axle  33  is axially suspended in the headrail  10 , having one end fixedly connected to the rotor (output shaft) of the reversible motor  32  and the other end pivoted to an axle holder  34  in the inside space of the headrail  10  at the left side. 
   The blind body  20  can be the slat assembly of a Venetian blind, the curtain of a window covering, or the like. According to this embodiment, the blind body  20  is a curtain having its top side fixedly connected in parallel to the periphery of the axle  33 . When starting the driving mechanism  30  to rotate the axle  33 , the axle  33  roll up/let off the blind body  20 , i.e., the axle  33  moves the blind body  20  to change its shading status. Therefore, the axle  33  works as a power output device  36  that moves the blind body  20 , and the reversible motor  32  works as a power input device  35  that moves the axle  33 . 
   The control mechanism  40  comprises a hollow suspension rod  41  and a controller  42 . The suspension rod  41  is vertically suspended from the headrail  10 , having one end, namely, the top end fixedly connected to the headrail  10  corresponding to the reversible motor  32 . The controller  42  comprises a handheld box  43  fixedly fastened to the other end, namely, the bottom end of the suspension rod  41  accessible to the hand of a person. As shown in  FIG. 2 , the handheld box  43  houses a circuit board  44 , which controls rotation (forward/backward rotation) and stoppage of the reversible motor  32 , and a battery set  45  electrically coupled to the circuit board  44 . The circuit board  44  has power input contacts (not shown). The battery set  45  has power output contacts (not shown). When inserted the battery set  45  into the handheld box  43 , the power output contacts of the battery set  45  are respectively maintained in contact with the power input contacts of the circuit board  44 , and therefore battery power is linked to the circuit board  44 . Lead wires  46  are inserted through the suspension rod  41  and electrically connected between the circuit board  44  and the reversible motor  32 . The handheld box  43  has control switches  47  located on the outside for controlling the operation mode of the circuit board  44 , and a detachable battery lid  48  corresponding to the battery set  45 . When detached the battery lid  48  from the handheld box  43 , the battery set  45  can easily be removed from the handheld box  43  for a replacement. 
   After detailed description of the structure and relative positioning of the parts of the first embodiment of the present invention, the operation of the electricity-operated window blind  100  is outlined hereinafter. 
   When wishing to change the shading status of the blind body  20 , the user can directly operate the control switches  47  of the controller  42  to rotate the reversible motor  32  forwards or backwards, or to stop the reversible motor  32 , thereby causing the shading status of the blind body  20  to be relatively changed. When the power of the battery set  45  of the controller  42  used up, the user can then open the battery lid  48  and then replace the battery set  45 . After installation of a new battery set, the battery lid  48  is closed again. 
   Because the suspension rod  41  holds the controller  42  at an elevation accessible to the hand of a person, the user can conveniently operate the controller  42  to control the shading status of the blind body  20 . When battery low, the user can conveniently replace the battery set  45 . 
     FIGS. 3 and 4  show an electricity-operated window blind  200  constructed according to the second preferred embodiment of the present invention. According to this embodiment, the electricity-operated window blind  200  comprises a headrail  50 , a blind body  60 , a driving mechanism  70 , and a control mechanism  80 . The headrail  50  and the blind body  60  are substantially similar to the like members in the aforesaid first embodiment. The main features of this second embodiment are outlined hereinafter. 
   The driving mechanism  70  comprises a motor drive  71  and a coupling device  75 . The motor drive  71  comprises a reversible motor  72  installed in the right side inside the headrail  50 , and an axle  73  coupled to the rotor (output shaft) of the reversible motor  72  and pivotally supported in an axle holder  74  in the left side inside the headrail  50 . The coupling device  75  is made of electrically insulative material and fixedly fastened to the headrail  50 , having a part extended out of the right bottom side of the headrail  50 . The coupling device  75  comprises connecting means  76  and terminals  78 . According to this embodiment, the connecting means  76  is an inner thread  77 . The terminals  78  are located on the top side of the coupling device  75 , and electrically coupled to the reversible motor  72 . According to this embodiment, the axle  73  works as a power output device  791 , and the reversible motor  72  and the coupling device  75  form a power input device  792  adapted to receive electric energy and to rotate the power output device  791 . 
   The control mechanism  80  comprises a hollow suspension rod  81  and a controller  82 . The suspension rod  81  is a hollow rod member of a predetermined length, having one end connected to the controller  82  and the other end provided with terminals  83 . The suspension rod  81  has coupling means  84 . According to this embodiment, the coupling means  84  is an outer thread  841  extended around the periphery of the end where the terminals  83  are provided. The outer thread  841  can be threaded into the inner thread  77  to force the terminals  83  into contact with the terminals  78 . Lead wires  86  are inserted into the suspension rod  81  and electrically connected between the terminals  83  and the circuit board  85  of the controller  82 . The circuit board  85  has a wireless receiving circuit adapted to receive control signal from a remote controller  87 . 
   When in use, the outer thread  841  of the suspension rod  81  is threaded into the inner thread  77  of the coupling device  75  to force the terminals  83  into contact with the terminals  78 , thereby causing the reversible motor  72  to be electrically coupled to the circuit board  85 , i.e., the terminals  78  of the coupling device  75  and the terminals  83  of the suspension rod  81  form a first interface and a second interface between the battery set  88  of the controller  82  and the reversible motor  72 , for enabling battery power supply to be provided by the battery set  88  to the reversible motor  72 . The user may operate the control switches  89  of the controller  82  to drive the circuit board  85  to start/stop the reversible motor  72 . Alternatively, the user can directly use the remote controller  87  to control the operation of the circuit board  85  at a remote place. 
   Further, when the blind body  60  moved to the desired position, the user can then disconnect the suspension rod  81  from the coupling device  74  and have the control mechanism  80  separately stored in a storage place, keeping the outer appearance of the window blind neat and clean. 
     FIG. 5  shows an electricity-operated window blind  300  constructed according to the third preferred embodiment of the present invention. This embodiment is substantially similar to the aforesaid second embodiment of the present invention with exceptions outlined hereinafter. 
   The power input device  91  of the driving mechanism  90  is formed of a reversible motor  911  and a hexagonal rod member  912 , which serve as the input device  91 . The reversible motor  911  is mounted inside the headrail  10 ′. The hexagonal rod member  912  is installed in the headrail  10 ′, having a bottom side extended out of the headrail  10 ′ toward the operation position of the user and a coupling portion  92 , for example, a V-groove  921  extended around the periphery near the bottom side, and a plurality of contacts  922  in the bottom edge of the bottom side. 
   The suspension rod  94  of the control mechanism  93  has a hexagonal coupling hole  941  in the top end, and retaining means  95  in the hexagonal coupling hole  941 . According to this embodiment, the retaining means  95  comprises a plurality of spring strips  951  vertically located on the peripheral wall of the hexagonal coupling hole  941 , each having a smoothly arched protruding portion  952  projecting toward the central axis of the hexagonal coupling hole  941 . The suspension rod  94  further has a plurality of terminals  953  respectively installed in the hexagonal coupling hole  941  and electrically connected to the battery set (not shown) of the controller (not shown) by lead wires  98 . The circuit board  97  of the controller is mounted inside the headrail  10 ′ and electrically connected to the reversible motor  911 . Lead wires  96  are inserted through the power input device  91  to electrically connect the circuit board  97  to the contacts  922 . 
   When in use, the user lift the suspension rod  94  to force the hexagonal coupling hole  941  into engagement with the power input device  91  of the driving mechanism  90 . At this time, the smoothly arched protruding portions  952  of the spring strips  951  are respectively forced into engagement with the V-groove  921 , keeping the suspension rod  94  firmly connected to the power input device  91 . At this time, the contacts  922  of the hexagonal rod member  912  are maintained in contact with the terminals  953  in the hexagonal coupling hole  941 , for enabling battery power supply to be transmitted from the controller through the lead wires  98 ,  96  to the circuit board  97  and then the reversible motor  911 . Further, because the spring strips  951  are deformable, the user can employ a force to the suspension rod  94 , keeping the suspension rod  94  connected to or disconnected from the power input device  91 .