Patent Publication Number: US-2022228431-A1

Title: Slat angle adjustment device for window blind

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to window blinds and more particularly, to a slat angle adjustment device for a window blind. 
     2. Description of the Related Art 
     TW Publication No. 201905314 discloses a detachable slat angle adjustment mechanism that allows a consumer to assemble the second shaft member with the first shaft member by himself/herself after purchase, such that the second shaft member won&#39;t be exposed to the outside of the headrail during packaging or delivery, avoiding accidental damage of the second shaft member and prohibiting the second shaft member from damaging the slats. 
     According to the aforesaid prior art, the first shaft member is hidden in the casing, so the positioning holes can&#39;t be seen from the outside, causing the consumer to adjust repeatedly the assembly angle of the second shaft member until the positioning protrusions of the second shaft member are engaged with the positioning holes of the first shaft member. As such, the aforesaid prior art is inconvenient in assembly. 
     SUMMARY OF THE INVENTION 
     It is a primary objective of the present invention to provide a slat angle adjustment device for a window blind, which can increase convenience in assembly. 
     To attain the above objective, the slat angle adjustment device of the present invention comprises a casing, a transmission unit, and a driving rod. The top end of the casing has two through holes at two opposite sides thereof, and the bottom end of the casing has a bottom hole, a wing accommodation space located above the bottom hole and in communication with the bottom hole, and a flange located between the bottom hole and the wing accommodation space. The transmission unit has a first worm shaft rotatably disposed in the casing and a second worm shaft rotatably disposed in the casing. The first worm shaft is provided with a first shaft portion, a first worm tooth portion formed on the outer surface of the first shaft, portion and located between two end portions of the first shall portion inserted into the through holes of the casing, and a non-circular transmission hole passing axially through the first shaft portion. The second worm shaft is provided with a second shaft portion, a second worm tooth portion formed on the outer surface of the second shaft portion and meshed with the first worm tooth portion of the first worm shaft, and a first assembling portion connected with the bottom end of the second shaft portion. The driving rod has a second assembling portion located in the casing and assembled with the first assembling portion of the second worm shaft, a flexible wing provided with a top end thereof connected with the outer surface of the second assembling portion and located in the wing accommodation space of the casing and engaged with the flange of the casing, and a third shaft portion provided with a top end thereof connected with the bottom end of the second assembling portion. When the driving rod is assembled, the second assembling portion of the driving rod is inserted into the casing through the bottom hole of the casing. During the insertion of the driving rod, the flexible wing is compressed by the flange. Once the flexible wing passes through the flange, the flexible wing is restored and engaged with the flange, and simultaneously, the second assembling portion of the driving rod is assembled with the first assembling portion of the second worm shaft. By this way, the assembly of the driving rod is completed. 
     It can be understood from the above illustration that the slat angle adjustment device of the present invention allows a consumer not to adjust repeatedly the assembly angle of the driving rod, thereby reducing assembly time and increasing assembly convenience. 
     Preferably, when the flexible wing is compressed by the flange, a part of the flexible wing is received in a recess of the second assembling portion to avoid mutual interference between the flexible wing and the second assembling portion. 
     Preferably, the wing accommodation space has a truncated cone cross-section with a diameter decreasing gradually away from the flange. 
     Preferably, the second worm shaft has a dish portion connected between the second shaft portion and the first assembling portion and inserted into an annular groove of the casing so as to perform convenient assembly of the second worm. 
     Preferably, the first assembling portion is a polygon post, and the second assembling portion has a polygon hole matched with the polygon post. After the second assembling portion is assembled with the first assembling portion, they aren&#39;t be rotated relative to each other, such that the second worm shaft can be driven by the driving rod to rotate. 
     Preferably, the transmission hole has a semicircular cross-section for insertion of a transmission shaft with a semicircular cross-section, such that the transmission shaft can be driven by the first worm shaft to rotate. 
     Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a slat angle adjustment device of the present invention. 
         FIG. 2  is an exploded perspective view of the slat angle adjustment device of the present invention. 
         FIG. 3A  is a sectional view of the slat angle adjustment device of the present invention, showing the flexible wing is compressed by the flange. 
         FIG. 3B  is similar to  FIG. 3A , showing the driving rod is assembled with the second worm shaft. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1, 2 and 3B , a slat angle adjustment device  10  of the present invention comprises a casing  20 , a transmission unit  30 , and a driving rod  60 . 
     The casing  20  includes two half shells  21   a,    21   b  fastened together. A through hole  22  is provided at each of left and right sides of the top end of the casing  20 . The two through holes  22  are communicated with each other through a first accommodation space  23 . Further, the casing  20  has a second accommodation space  24  at one side of the first accommodation space  23  and in communicating with the first accommodation space  23 . As shown in  FIG. 3B , the casing  20  has an annular groove  25  located under the second accommodation space  24 , a receiving hole  26  in communicating with the annular groove  25 , a wing accommodation space  27  in communicating with the receiving hole  26 , and a bottom hole  28  in communicating with the wing accommodation space  27 . The wing accommodation space  27  and the bottom hole  28  are divided by a flange  29 . The wing accommodation space  27  has a truncated cone cross-section with a diameter decreasing gradually away from the flange  29 . 
     As shown in  FIGS. 2 and 3B , the transmission unit  30  has a first worm shaft  40  provided with a first shaft portion  41 , a first worm tooth portion  43  formed on the outer surface of the first shaft portion  41  and located between two end portions  42  of the first shaft portion  41 , and a non-circular transmission hole  44  (by taking semicircle as an example) passing axially through the first shaft portion  41 . The first worm shaft  40  is rotatably disposed in the casing  20  in such manner that the two end portions  42  of the first shaft portion  41  are inserted into the through holes  22  of the casing  20 , and the first worm tooth portion  43  are located at the first accommodation space  23  of the casing  20 , and the transmission hole  44  is engaged with a transmission shaft  74 , which has the same cross-section as the transmission hole  44  (as shown in  FIG. 1 ). 
     As shown in  FIGS. 2 and 3B , the transmission unit  30  further has a second worm shaft  50  provided with a second shaft portion  51 , a second worm tooth portion  52  formed on the outer surface of the second shaft portion  51 , and a first assembling portion  53  (by taking a polygon post as an example) connected with the bottom end of the second shaft portion  51  through a dish portion  54 . The second worm shaft  50  is rotatably disposed in the casing  20  in such a manner that the second worm tooth portion  52  and the first assembling portion  53  are respectively located at the second accommodation space  24  and the receiving hole  26 , and the dish portion  54  is inserted in the annular portion  25 , and the second worm tooth portion  52  is engaged with the first worm tooth portion  43  of the first worm shaft  40 . By this way, the first worm shaft  40  is driven by the second worm shaft  50  to rotate. 
     The driving rod  60  includes a second assembling portion  61 , two flexible wings  64 , and a third shaft portion  65 . The second assembling portion  61  has a polygon hole  62 . The flexible wings  64  are located at two opposite sides of the second assembling portion  61  and each have a top end thereof connected with the outer surface of the second assembling portion  61 . The top end of the third shaft portion  65  is connected with the bottom end of the second assembling portion  61 , and the bottom end of the third shaft portion  65  has a hook hole  66 . As shown  FIGS. 3A and 3B , when assembled, the second assembling portion  61  of the driving rod  60  is inserted in the casing  20  through the bottom hole  28  of the casing  20 . During the insertion of the driving rod  60 , the flexible wings  64  are compressed by the flange  29 . Once the flexible wings  64  pass through the flange  29 , the flexible wings  29  are restored and located in the wing accommodation space  27  of the casing  20  and engaged with the flange  29 . At the same time, the polygon hole  62  of the second assembling portion  61  are engaged with the first assembling portion  53  of the second worm shaft  50 , such that the second worm shaft  50  can be driven by the driving rod  60  to rotate, thereby performing the assembly of the driving rod  60 , After the assembly of the driving rod  60 , the bottom end of the third shaft portion  65  protrudes from the casing  20 . Thus, a hook portion  72  of an adjusting rod  70  can be hooked by a user in the hook hole  65  of driving rod  60  and then the adjusting rod  70  is forced by the user to rotate. During rotation of the driving rod  60 , the second worm shaft  50  is driven by the driving rod  60  to rotate the first worm shaft  40 , causing rotation of transmission shaft  74  and other coupled transmission component parts (such as rotary drum and ladder cord) and adjustment of the angular position of slats of a window blind (not shown). 
     It deserves to be mentioned that the second assembling portion  61  is provided with two recesses  63  at a bottom end thereof. As shown  FIGS. 2 and 3A , the two recesses  63  are corresponding to the two flexible wings  64  in a one-to-one manner. As such, when the flexible wings  64  are compressed by the flange  29 , a part of each of the flexible wings  64  is received in one respective recess  63  to avoid mutual interference between the flexible wings  64  and the second assembling portion  61 . 
     As described above, the first worm shaft  40  and the second worm shaft  50  are mounted inside the casing  20 , and the driving rod  60  is a separated component that is assembled with the casing  20  by means of the engagement between the flexible wings  64  and the flange  29 , that is to say, the slat angle adjustment device  10  of the present invention allows a consumer to assemble the driving rod  60  with the second worm shaft  50  by himself/herself after purchase, so it is unnecessary for the consumer to adjust repeatedly the assembly angle of the driving rod  60 , thereby reducing assembly time and increasing assembly convenience.