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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention The present invention relates to a device for a motorized shutter assembly, particularly a louver blade positioning device of a motorized shutter assembly. 
         [0002]    2. Description of the Prior Art 
         [0003]    Referring to  FIG. 1A , a conventional motorized shutter assembly  11  primarily includes a plurality of louver blades  13  and a push rod  12  driven by a motorized module  10  in order to drive the plurality of louver blades  13  in linkages and to adjust an angle of louver blades in a motorized manner through a remote control  101 . 
         [0004]    Referring to  FIG. 1B , the motorized module  10  includes a motor  102  and a transmission mechanism  103  to drive in reversible movement of the louver blades  13  through a driving shaft  104 . In addition to motorized operations, ordinary motorized shutter assembly can be manually operated by pushing the push rod  12  in order to adjust an angle of louver blades as shown in  FIGS. 1C and 1D . However, when one manually pushing the push rod  12  upward to close the plurality of louver blades  13 , the louver blades  13  become titled toward Position “b” from the manually closed Position “a” due to the dead weight in response to the weight of the louver blades  13  and the push rod  12  and/or the clearance inherent between elements of the transmission mechanism in the motorized module  10  as shown in  FIG. 1D . Consequently, this causes the disadvantage of unsatisfactory manual closure. Moreover, during motorized operations, several sets of motorized shutters may encounter an angular variance under the same control command possibly due to the clearance among the elements. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention is to provide a louver blade positioning device of a motorized shutter assembly, such that the louver blades can be effectively positioned at a specific angle, for example, full-closed or at a specific angle as desired. 
         [0006]    The present invention provides a louver blade positioning device of a motorized shutter assembly, including an indented positioning portion or a protruded portion formed upon a driving shaft for driving louver blades and a resilient member formed on a suitable position of the shutter assembly. The predetermined portion of the resilient member moves toward the driving shaft and is inserted into the indented positioning portion or the protruded portion when the louver blades connected to the driving shaft are rotated to approach a specific angle. Through the resilient force exerted by the resilient member on the indented positioning portion or the protruded portion, the driving shaft rotates to approach a specific angle, such that the louver blades are rotated automatically toward a predetermined angle and become positioned when being rotated to approach the angle, thereby becoming free from the angular clearance among transmission components of the motorized shutter assembly. 
         [0007]    The advantage of the present invention is that the louver blades of the louver blade positioning device of the motorized shutter assembly made according to the present invention can automatically be positioned at a specific angle through manual or electrical operations in order to become free from the clearance between the motor and the transmission mechanism. In this way, the louver blades are manually closed tightly or a plurality of louver blades of the motorized shutter assembly is easily positioned at a consistent, specific angle under motorized or manual operations. 
         [0008]    Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCIPTION OF THE DRAWINGS 
         [0009]    The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein. 
           [0010]      FIG. 1A  shows a schematic perspective view of a conventional louver blade positioning device of the motorized shutter assembly. 
           [0011]      FIG. 1B  is a schematic view illustrating the structure of the motorized module capable of adjusting louver blades made according to  FIG. 1A . 
           [0012]      FIG. 1C  and  FIG. 1D  are schematic views illustrating the adjusting performance of the louver blade of the motorized module made according to  FIG. 1A . 
           [0013]      FIG. 2  is a structural view illustrating a first embodiment of the resilient member made according to the present invention. 
           [0014]      FIG. 3  illustrates a perspective view of a driving shaft made according to  FIG. 2 . 
           [0015]      FIGS. 4A and 4B  are schematic views illustrating the structure and the function of a resilient member made according to a first embodiment of the present invention. 
           [0016]      FIG. 5A  to  FIG. 5E  illustrate different configurations of an elastic element and an inserted element of the resilient member made according to the first embodiment of the present invention. 
           [0017]      FIG. 6A  is a view illustrating a resilient member made according to a second embodiment of the present invention. 
           [0018]      FIG. 6B  and  FIG. 6C  are schematic views illustrating the structure and the function of a resilient member made according to the second embodiment of the present invention. 
           [0019]      FIG. 7A  is another embodiment illustrating variations of an elastic element in the resilient member made according to the second embodiment of the present invention. 
           [0020]      FIG. 7B  and  FIG. 7C  are schematic views illustrating variations in the structure and the function of an elastic element in the resilient member made according to the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    As shown in  FIG. 2  to  FIG. 4B , they are schematic views illustrating the structure of a resilient member of a louver blade positioning device of a motorized shutter assembly according to the first embodiment of the present invention. A motorized module  10  of a shutter assembly  11  includes a first housing  21  and a second housing  22  coupled together, housing a transmission mechanism  23 , including a motor  231  and a gear  232 , as well as a driving shaft  24  therein. In conjunction with the driving shaft  24 , a louver blade  30  is driven to rotate. The motor  231  is a direct current, an alternating current or a stepper motor capable of reversible motions, such that the louver blade  30  rotates forward or backward accordingly. The transmission mechanism  23 , usually having a torque limiter or a clutch means (not shown in the drawing), facilitates the manual operations and rotations of the louver blade  30 , without damaging the motor  231  or the transmission mechanism  23 . 
         [0022]    To adjust and restore the louver blade  30  and the driving shaft  24  to their respective original positions when approaching a specific angle, the driving shaft  24  of the present invention includes a shaft  242 , rotated and pivotally formed between the first housing  21  and the second housing  22 , with an end of the driving shaft  24  formed into a louver blade-connecting end  243  capable of connecting a louver blade to another louver blade. A gear  241  formed on an end of the shaft  242  engages with the transmission mechanism  23 . One (or more than one) indented positioning portion  41  is arranged and disposed on a circumference of the shaft  242 . A set of resilient members  50 , formed in a spring slot  53  of the second housing  22 , includes an elastic element  51  and an inserted element  52 . Constantly being pushed against the elastic member  51 , the inserted element  52  moves toward the shaft  242  but it only moves back and forth along a longitudinal axis of the spring slot  53 , without departing from the spring slot  53 . 
         [0023]    In this embodiment, the elastic element  51  is in the form of a helical spring and the inserted element  52  is in the form of a bearing ball. The longitudinal axis of the spring slot  53  is perpendicular to an axis of the driving shaft  24 . A guided portion is an arc constituted on a surface of the bearing ball. The longitudinal axis of the spring slot  53  or the movement direction of the inserted element  52  is defined as an included angle not perpendicular (oblique) to an axis of the driving shaft  24  so as not to affect the desirably positioning of the driving shaft  24  at a specific angle. 
         [0024]    Referring to  FIG. 4A , a spring formed in the spring slot  53  pushes against the inserted element  52  such that the spring is exactly inserted into an indented positioning portion  41  of the driving shaft  24 , because the force F 0  perpendicularly exerted by the spring on the center of rotation of the driving shaft  24  fixes the driving shaft  24  at a predetermined angle. 
         [0025]    When the driving shaft  24  rotates to approach the predetermined angle (for example, at the location shown in  FIG. 4B ), the force F 0  exerted by the spring pushes against the inserted element  52 , such that the inserted element  52  comes into contact with a contact point  411  on an outer circumference of the driving shaft  24  close to the indented positioning portion  41  through an arc-shaped guided portion. The contact point  411  makes an angle of deflection with the force F 0 , such that the force F 0  produces a component of force F 1 , driving the driving shaft  24  to rotate and reach a stable positioning state as shown in  FIG. 4A . In other words, when the driving shaft  24  rotates to approach the specify angle, the driving shaft  24  automatically becomes positioned. 
         [0026]      FIGS. 5A to 5E  illustrate variations of the resilient member made according to the present invention. The inserted element  52  is formed in the shape of a cone (thereby forming the guided portion with an inclined plane on a top thereof) as shown in  FIG. 5A , while the indented positioning portion  41  has a square-shaped cross-section, while the inserted element  52  is a cuboid having a lead angle as shown in  FIG. 5B . Referring to  FIG. 5C , a plurality of the indented positioning portions  41  are formed upon the driving shaft  24  to create more fixed angles. Referring to  FIG. 5D , the indented positioning portion  41  of the driving shaft  24  is constituted into a protruded part  244  such that the inserted element  52  is transformed into a shallow indented portion. Referring to  FIG. 5E , the elastic element  51  and the inserted element  52  are formed into an oblique angle, thus forming an indented positioning portion  41  in conjunction with the driving shaft  24 . 
         [0027]      FIG. 6A  is a view illustrating a resilient member made according to a second embodiment of the present invention. The elastic element  51  of the resilient member  50  in the shape of a spring and the inserted element  52  integrated in the form of a protrusion on the spring respectively replace the spring and bearing ball in the previous embodiments. The spring is fixed on the first housing  21  at two ends thereof, to support the deformation under the operation of an external force as shown in  FIG. 6A , thereby producing a force F 0 . 
         [0028]      FIG. 6B  and  FIG. 6C  are schematic views illustrating the function of a resilient member made according to the second embodiment of the present invention. In  FIG. 6B , the protrusion on the spring exactly fits into the indented positioning portion  41  of the driving shaft  24 . Given the force F 0  acted upon by the protrusion perpendicular to the center of rotation of the driving shaft  24 , the driving shaft  24  is maintained at a steady state as soon as it rotates to a specific angle. When the driving shaft  24  rotates to approach to the specific angle (in the location as shown in  FIG. 6C ), the force F 0  produces a component of force F 1  due to the force F 0  acted by the protrusion on a contact point  54  at a corner of the indented positioning portion  41  as well as the angle of deflection between the contact point  54  and the force F 0 . At that instant, the driving shaft  24  is made to rotate to approach to a stable positioning state as shown in  FIG. 6B . In other words, when the driving shaft  24  rotates to approach a steady angle, the resilient member  50  forces the driving shaft  24  to continue rotating until it reaches a stable location for positioning. 
         [0029]      FIG. 7A  is another embodiment illustrating variations of an elastic element in the resilient member made according to the second embodiment of the present invention. In  FIG. 7A , the elastic element  51   a  of the resilient member  50   a  in the shape of a spring and the inserted element  52   a  integrated in the form of an indented opening on the spring, respectively replace the spring and the bearing ball as shown in the first embodiment. The spring is fixed on the first housing  21  at two ends thereof, in order to support the deformation under the operation of an external force as shown in  FIG. 7A , thereby producing a force F 0 . The indented positioning portion  41  on a circumference of the driving shaft  24  is formed into a protrusion corresponding to the indentation. 
         [0030]      FIG. 7B  and  FIG. 7C  are schematic views illustrating variations in the function of an elastic element in the resilient member made according to the second embodiment of the present invention. In  FIG. 7B , the inserted element  52   a  on the spring exactly fits into the positioning portion  41  of the protruded part  244  of the driving shaft  24 . Given the force F 0  acted upon by the inserted element  52   a  toward the center of rotation of the driving shaft  24 , the driving shaft  24  is steadily formed into a specific angle. When the driving shaft  24  rotates to approach to the specific angle (in the location as shown in  FIG. 7C ), the force F 0  of the inserted element  52   a  pushes against a contact point  54   a  on a circumference of the driving shaft  24  near the positioning portion  41 . The contact point  54   a  makes an angle of deflection with the force F 0 , such that the force F 0  produces a component of force F 1 , driving the driving shaft  24  to rotate and reach a stable positioning state as shown in  FIG. 7C . In other words, when the driving shaft  24  rotates to approach the specify angle, the resilient member  50   a  forces the driving shaft  24  to continue rotating to a steady location for positioning. 
         [0031]    The present embodiment is formed into an indented positioning portion  41  or a protruded part  244  of a driving shaft  24 , such that the driving shaft  24  is horizontally extended. For practical applications, the driving shaft  24  is formed relative to more than two positioning portions with a predetermined angle with the axis of the driving shaft. For example, one angle makes the louver blade  30  in a closed position while another angle makes the louver blade  30  horizontally open. Given this structure, when the louver blade  30  is manually or electrically rotated to approach the specific angle, the louver blade  30  automatically approaches the specific angle and becomes positioned, thereby overcoming the drawback of having clearance between the motor and the transmission mechanism. In this way, the louver blade is maintained manually closed or a plurality of the louver blades of the motorized shutter assembly can easily become positioned at a specific angle by motorized or manual operations. The aforesaid positioning portion and the inserted element can be formed on a driving shaft (for example, the transmission mechanism) outside the driving shaft  24 . Moreover, the present invention can be applied for slats positioning of conventional blind products too. 
         [0032]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Summary:
A louver blade positioning device of a motorized shutter assembly includes an indented positioning portion or a protruded portion formed upon a driving shaft and a resilient member coming into contact with the driving shaft and the indented positioning portion or the protruded portion in a radically movable manner at a fixed angle. When the louver blades are rotated to approach a specific angle, the resilient member moves into the indented positioning portion or the protruded portion. Through the resilient force exerted by the resilient member on the indented positioning portion or the protruded portion, the driving shaft rotates to approach the specific angle, such that the louver blades become positioned at the specific angle when being rotated to approach the specific angle, thereby becoming free from the angular clearance inherent among transmission components of the motorized shutter assembly.