Patent Publication Number: US-2010122779-A1

Title: Venetian blind

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a venetian blind, and more specifically to a venetian blind that has a simple structure and a low manufacturing cost. 
     2. Description of the Related Art 
       FIG. 1  shows a conventional venetian blind  10  comprising an upper beam  11 , two retainers  12  mounted to the upper beam  11 , four ladder tapes  13  connected to the retainers  12  in pairs, a plurality of slats  14  connected to the ladder tapes  13 , an adjuster  15  mounted to the upper beam  11 , a cord  16  connected to the adjuster  15 , and a driving rod  17  passing through the retainers  12  and the adjuster  15 . 
     Referring to  FIG. 1A , when a user pulls the cord  16  downward, an inner gear of the adjuster  15  can be rotated to force the retainers  12  to rotate synchronously through the driving rod  17 , such that the slats  14  can be driven by the retainers  12  to rotate through the ladder tapes  13 , thereby attaining the purpose of adjusting the light. 
     As described above, the conventional venetian blind  10  needs to be equipped with many components, such as the retainers  12 , the adjuster  15  and the driving rod  17 , for rotation of the slats  14 , so it can be seen that the conventional venetian blind  10  has the drawbacks of having complicated structure and high manufacturing cost. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished in view of the above-noted circumstances. It is one objective of the present invention to provide a venetian blind that has a simple structure and a low manufacturing cost. 
     To achieve this objective of the present invention, the venetian blind comprises a rotatable upper beam, a plurality of slats, two ladder tapes connected with two opposite sides of the slats and each having a top end fixed to the upper beam, and two cords each having a top end connected with the upper beam to drive the upper beam to rotate in opposite directions. 
     When one of the cords is pulled, the upper beam can be rotated clockwise to force the slats to rotate through the ladder tapes, thereby blocking the light. When the other one of the cords is pulled, the upper beam can be rotated counterclockwise to drive the slats to rotate, thereby allowing the light to pass between the slats. 
     Accordingly, the venetian blind of the present invention uses a simple structure to control the rotation of the slats so as to reduce the manufacturing cost, thereby achieving the objective of the present invention. 
     Further scope of 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 DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a perspective view of a venetian blind according to a prior art; 
         FIG. 1A  is an enlarged view of a portion encircled by circle A in  FIG. 1 ; 
         FIG. 2  is a partially exploded view of a venetian blind according to a preferred embodiment of the present invention; 
         FIG. 3  is an exploded view of the left bracket and the upper beam of the venetian blind according to the preferred embodiment of the present invention; 
         FIG. 4  is a perspective view of the venetian blind according to the preferred embodiment of the present invention, showing that the slats are rotated to allow the light to pass through; 
         FIG. 5  is another perspective view of the venetian blind according to the preferred embodiment of the present invention, showing that the slats are rotated to block the light, and 
         FIG. 6  is a perspective view of the venetian blind according to the preferred embodiment of the present invention, showing that the slats are overlapped. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 2 and 4 , a venetian blind  20  in accordance with a preferred embodiment of the present invention comprises an upper beam  30 , a lower beam  40 , a plurality of slats  50 , two pairs of ladder tapes  52 , a lifting cord  60 , a left bracket  70 , a right bracket  80 , a first light-adjusting cord  90 , and a second light-adjusting cord  92 . 
     As shown in  FIGS. 2 and 3 , the upper beam  30  has, but not limited to, a circular crosssection. The upper beam  30  has a left end portion  32 , two first grooves  322  and  324  at an outer periphery of the left end portion  32 , a left recess  326  between the first grooves  322  and  324 , a right end portion  34 , and a right recess  342  at an outer periphery of the right end portion  34 . 
     The lower beam  40  has, but not limited to, a rectangular crosssection. The lower beam  40  is located under the upper beam  30 . 
     The slats  50  are spacedly suspended between the upper beam  30  and the lower beam  40  by means of the ladder tapes  52  and strips  54  passing though the slats  50 . 
     The ladder tapes  52  are connected with two opposite sides of the slats  50 , and respectively provided with a top end fixed to the upper beam  30  and a bottom end fixed to the lower beam  40 . 
     The lifting cord  60  has a top end penetrating into the upper beam  30  and connected with a pulley device (not shown) in the upper beam  30 , and a bottom end suspended downward. By means of pulling the bottom end of the lifting cord  60 , the slats  50  can be lifted upward to overlap each other through the pulley device, as shown in  FIG. 6 . 
     As shown in  FIG. 3 , the left bracket  70  includes a left bracket base  72  capable of fastening to a wall or a window frame, and a left bracket cover  74  having two second grooves  742  and  744  at an inner periphery thereof, a left protrusion  746  between the second grooves  742  and  744 , a first through hole  76 , and a second through hole  78 . When the left bracket  70  is assembled to the left end portion  32  of the upper beam  30 , the left protrusion  746  of the left bracket cover  74  is engaged with the left recess  326  of the upper beam  30 , and the second grooves  722  and  744  of the left bracket cover  74  are respectively corresponding to the first grooves  322  and  324  of the upper beam  30 . 
     The right bracket  80  includes a right bracket base  82  capable of fastening to the wall or the window frame, and a right bracket cover  84  having a right protrusion  842  at an inner periphery thereof. When the right bracket  80  is assembled to the right end portion  34  of the upper beam  30 , the right protrusion  842  of the right bracket cover  84  is engaged with the right recess  342  of the upper beam  30 . 
     The first light-adjusting cord  90  is wound around the left end portion  32  of the upper beam  30  clockwise along the first groove  322  of the upper beam  30  and the second groove  742  of the left bracket cover  74 , and provided with a top end fixed to the left end portion  32  of the upper beam  30  and a bottom end passing through the first through hole  76  of the left bracket cover  74  to be suspended downward. Therefore, when the bottom end of the first light-adjusting cord  90  is pulled, the upper beam  30  can be rotated clockwise. 
     The second light-adjusting cord  92  is wound around the left end portion  32  of the upper beam  30  counterclockwise along the first groove  324  of the upper beam  30  and the second groove  744  of the left bracket cover  74 , and provided with a top end fixed to the left end portion  32  of the upper beam  30  and a bottom end passing through the second through hole  78  of the left bracket cover  74  to be suspended downward, such that the upper beam  30  can be rotated counterclockwise by pulling the bottom end of the second light-adjusting cord  92 . 
     When a user pulls the first light-adjusting cord  90 , the upper beam  30  can be rotated clockwise to force the slats  50  to rotate through the ladder tapes  52 , as shown in  FIG. 5 , and when the pulling force is released, the upper beam  30  can stop rotating by means of the friction force generated between the left and right protrusions  746  and  842  and the left and right recesses  326  and  342  for enabling the slats  50  to tilt to one side, thereby blocking the light. Thereafter, when the user pulls the second light-adjusting cord  92  to drive the upper beam  50  to rotate counterclockwise, the slats  50  can be forced to rotate for allowing the light to pass through, as shown in  FIG. 4 . 
     Besides, when the user pulls the lifting cord  60 , the lower beam  40  can move upward to cause the slats  50  to overlap each other through the gear device in the upper beam  30 . 
     Compared to the conventional venetian blind of the prior art, the venetian blind of the present invention provides two light-adjusting cords and the rotatable upper beam to control the rotation of the slats without installing complicated components, such as the adjuster, the retainers, and the driving rod, so that the venetian blind of the present invention has the advantages of having simple structure and low manufacturing cost. 
     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.