Patent Publication Number: US-2007119547-A1

Title: Cordless window blind structure

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to a cordless window blind structure, comprising a head rail having a fixed seat and a cord-winding control unit with an operating cord attached thereto respectively mounted at both ends, and a movable seat situated there-between wherein the operating cord is attached to the movable seat at one end, and retrieving cords are wound onto the fixed seat and the movable seat thereof, permitting the operating cord and the retrieving cords to reciprocally associate with each other in linking operation so that a bottom rail is simply pushed or pulled by hands to loosen or tighten the retrieving cords and actuate the movement of the operating cord therewith to form a state of counterbalance there-between for easy adjustment of the blind body into a desirable position thereby.  
      A conventional window blind structure is usually made up of a blind body, an operating drive assembly, and a pull cord. In operation, the pull cord is drawn by force exerted by hands of a user, and the small frictional surface of the pull cord tends to rub against the hands exerting force thereon and, thus, hurt the area of hands contacting with it. Besides, in case of an excessive down-pulling force exerted onto the pull cord or a sudden release at great speed, the blind body cannot be accurately positioned in a desirable position and the adjustment process must be repeated over again, which is quite inconvenient in operation.  
     SUMMARY OF THE PRESENT INVENTION  
      It is, therefore, the primary purpose of the present invention to provide a cordless window blind structure wherein pushing or pulling force is exerted by hands of a user to cooperatively work with the elasticity generated by torsion springs mounted to a cord-winding control unit, permitting the user to freely adjust a blind body into a desirable position without getting hurt on the hands as shown in the conventional pulling cord above to achieve the best application state thereby.  
      It is, therefore, the second purpose of the present invention to provide a cordless window blind structure wherein pushing or pulling force is exerted by the hands to cooperatively work with the elasticity generated by the torsion springs of the cord-winding control unit, permitting the blind body to precisely locate in a desirable expanded or collected position as pulled or pushed by the hands of the user in operation without the inconvenience of repeated readjustment caused by the above conventional pull cord to achieve an accuracy and simplicity in operation as well as in assembly thereof.  
      It is, therefore, the third purpose of the present invention to provide a cordless window blind structure wherein a movable seat and a fixed seat are respectively equipped with a dividing board to divide a set of upper and lower winding spaces thereon and a separating board to separate a set of upper and lower winding grooves thereon, permitting the retrieving cords to accurately wind onto a set of first and second gliding elements of the dividing board and a set of first, second, and third sliding elements of the separating board for separation and guiding purposes so that the blind body can be easily and smoothly expanded and collected without the retrieving cords being entangled and caught immovable in operation thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded perspective view of the present invention.  
       FIG. 2  is an enlarged perspective view of a fixed seat of the present invention.  
       FIG. 3  is an assembled cross sectional view of the present invention.  
       FIG. 4  is a diagram showing a blind body of the present invention operated to expand downward in application.  
       FIG. 5  is a diagram showing the blind body of the present invention operated to collect upwards in application.  
       FIG. 6  is another assembled cross sectional view of the present invention.  
       FIG. 7  is a third assembled cross sectional view of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Please refer to  FIG. 1  showing an exploded perspective view of the present invention. The present invention relates to a cordless window blind structure, comprising a head rail  10 , a bottom rail  20 , a cord-winding control unit  30 , a fixed seat  40 , a movable seat  50 , and a blind body  60  wherein the head rail  10  has a set of first and second accommodating cavities  11 ,  12  indented at both ends thereon, and a plurality of cord-passages  13  disposed at the bottom surface thereon for the extension of retrieving cords  14  there-through respectively. Each retrieving cord  14  is guided to pass through the blind body  60  and attach to the bottom rail  20  at the bottommost end thereof. The cord-winding unit  30  has a rotary seat  31  mounted therein, and an operating cord is fixed to the rotary seat  31  at one end thereof. The lower end of the rotary seat  31  has a set of torsion springs  33  attached to both lateral sides thereon, permitting the torsion springs  33  actuated by the movement of the operating cord  32  and the clockwise or counterclockwise rotation of the rotary seat  31  to counter-wind or recoil and elastically position thereby. The fixed seat  40  (molded in an inverted U-shaped configuration) and the movable seat  50  are respectively equipped with a middle separating board  41  and a middle dividing board  51  to form a set of upper/lower winding grooves  42 ,  43 , and a set of upper/lower winding spaces  52 ,  53  thereon. The upper winding groove and winding space  42 ,  52  have a set of first and second sliding elements  44 ,  45  with a rod-like fixing element  46 , and a set of first and second gliding elements  54 ,  55  with a positioning element  56  extending at appropriate positions thereon respectively. The first and second sliding elements  44 ,  45  of the fixed seat  40  and the first and second gliding elements  54 ,  55  of the movable seat  50  are symmetrically arranged to align side by side in spacing respectively. And the fixing element  45  of the fixed seat  40  is located at one side of the second sliding element  45  thereof, while the positioning element  56  of the movable seat  50  is situated at one side of the dividing board  51  symmetrically opposite to the first and second gliding elements  54 ,  55  thereof. The fixed seat  40  is also provided with a third sliding element  47  at the lower winding groove  43  thereon, and the movable seat  50  has support legs  57  extending at the lower winding space  53  thereon wherein the third sliding element  47  are disposed precisely protruding at one side of the separating board  41  as shown in  FIG. 2 . The retrieving cords  14  and the operating cord  32  can be made of straps or ropes, etc.  
      Please refer to  FIG. 3  showing an assembled cross sectional view of the present invention. The movable seat  50  is guided from one side of the first accommodating cavity  11  to slide into the head rail  10  in restricting location therein. Then, the cord-winding control unit  30  and the fixed seat  40  are respectively mounted into the first and the second accommodating cavities  11 ,  12  and firmly positioned therein, permitting the movable seat  50  to precisely situate between the cord-winding unit  30  and the fixed seat  40  thereby. The retrieving cords  14  are respectively guided through the bottom surface of the head rail  10  to run along the lower winding space  53  of the movable seat  50  and the lower winding groove  43  of the fixed seat  40  respectively before synchronically led to wind around the third sliding element  47  and further extend from the separating board  41  of the upper winding groove  42  to the dividing board  51  of the upper winding space  52  thereof. Then, the retrieving cords  14  are guided in consecutive S-shaped manner to wind onto the first gliding element  54 , the second sliding element  45 , and then the second gliding element  55  in a sequence before each retrieving cord  14  is synchronically led to attach to the fixing element  46  thereon. And, the other end of the operating cord  32  attached to the cord-winding control unit  30  at one end thereof is fixed to the positioning element  56  of the movable seat  50 , permitting the operating cord  32  and the retrieving cords  14  to reciprocally associate with each other in linking operation so as to actuate the movable seat  50  thereby, completing the assembly of the present invention.  
      In application, when the blind body  60  as shown in  FIG. 4  is to be expanded downwards, the bottom rail  20  is pulled downwards by hands. Then, the retrieving cords  14  drawn by the bottom rail  20  at the bottommost ends will run along the first and second sliding and gliding elements  44 ,  45 ,  54 ,  55  of the fixed seat  40  and the movable seat  50  respectively and stretch along the separating and dividing boards  41 ,  51  and the third sliding element  47  thereof to lower downwards thereby. The movable seat  50  pulled by the lowered retrieving cords  14  will slide towards the fixed seat  40  accordingly, and the operating cord  32  drawn by the movable seat  50  therewith will actuate the rotary seat  31  of the cord-winding control unit  30  to revolve in clockwise rotation. Meanwhile, the two torsion springs  33  juxtaposed and connected to both lateral sides of the rotary seat  31  to augment the elasticity thereby will be affected by the pulling forcing to revolve counterclockwise in an S shape rotation with a constant torque naturally occurred to counter wind onto the rotary seat  31  till coiled tight thereon. Furthermore, the constant torque occurred works in a linear operation and the torque will not be altered due to the increase of the coils counter wound thereon, reinforcing the strengthen of the blind body  60  affected by the pulling force to achieve efficient suspension thereby.  
      When the blind body  60  as shown in  FIG. 5  is to be collected upwards, the bottom rail  20  is pushed upwards by hands, and the counter-wound torsion springs  33  will be released to naturally recoil backwards, permitting the rotary seat  31  to revolve in counterclockwise rotation with a constant torque occurred at the same time. Then, the movable seat  50  will be freed from the pulling force of the loosened retrieving cords  14 , and actuated by the pulling force of the withdrawing operating cord  32  to slide towards the cord-winding control unit  30 . Meanwhile, the retrieving cords  14  are actuated by the sliding movement of the movable seat  50  to run around the first and the second gliding elements  54 ,  55  and retrieve upwards so as to collect the blind body  60  thereby. Therefore, via the pushing and pulling forces exerted by the hands to cooperatively work with the cord-winding control unit  30  with constant torque occurred in linking operation thereof, the present invention can refrain the hands from getting hurt by the above-mentioned pull cord so that a user can freely adjust the blind body  60  into a desirable position to achieve the best application state thereby. In addition, the movable seat  50  and the fixed seat  40  are respectively equipped with the dividing board  51  with the upper and lower winding spaces  52 ,  53  and the separating board  41  with the upper and lower winding grooves  42 ,  43  so that the retrieving cords  14  can be accurately and sequentially wound onto the first and second gliding elements  54 ,  55  and the first, second, and third sliding elements  44 ,  45 ,  47  thereof respectively to achieve separation and guiding purposes thereby. Thus, the blind body  60  can be easily and smoothly expanded and collected without the retrieving cords  14  being entangled or caught immovable in operation.  
      Please refer to  FIG. 6  showing another assembled cross sectional view of the present invention. The first gliding element  54  of the movable seat  50  and the first sliding element  44  of the fixed seat  40  can be alternatively arranged to situate at the rear side of the second gliding element  55  and the second sliding element  45  in spacing respectively.  
      Please refer to  FIG. 7  showing a third assembled cross sectional view of the present invention. The second gliding element  55  of the movable seat  50  and the second sliding element  45  of the fixed seat  40  can also be alternatively arranged to situate at the rear side of the first gliding element  54  and the first sliding element  44  in spacing respectively.