Window blind structure

Abstract

A window blind structure comprises a beaded-chain control unit with a positioning seat and a cord-winding device accommodated to one end of a head rail, and left/right drive-control pulley assemblies mounted to both ends of the head rail for the winding of pull cords synchronically attached to an actuating cord at one end and guided through a blind body to fix onto a bottom rail at the other end respectively. The positioning seat has an assembly cavity with through holes defining thereon precisely matched to a roller shaft of a two-way rotary cylinder of the cord-winding device, permitting the actuating cord to pass through the through holes and attach onto the roller shaft. Therefore, the actuating cord, drawn to coil up or release depending on the revolving direction of the roller shaft, can move the pull cords and the bottom rail therewith to collect or expand the blind body thereby.

1 . A window blind structure, comprising a beaded-chain control unit made up of a positioning seat and a cord-winding device that is accommodated to one end of a head rail, and a set of left/right drive-control pulley assemblies are mounted to both ends of the head rail for the winding of a plurality of pull cords that, sequentially running through the left/right drive-control pulley assemblies, are synchronically attached to an actuating cord at one end, and led through a blind body to fix to a bottom rail at the other end respectively wherein the positioning seat has an assembly cavity with through holes defining the interior therein, and the cord-winding device has a two-way rotary cylinder with a roller shaft precisely matched to the through holes of the positioning seat thereof so that the actuating cord can be guided through the through holes to attach onto the roller shaft thereby; therefore, the actuating cord is drawn to coil up or release depending on the revolving direction of the roller shaft, which will actuate the synchronic movement of the pull cords and the bottom rail in linking operation so as to collect or expand the blind body thereby.  
     
     
         2 . The window blind structure as claimed in  claim 1  wherein the through holes of the positioning seat thereof can be symmetrically disposed at both lateral sides of the assembling cavity thereon.  
     
     
         3 . The window blind structure as claimed in  claim 1  wherein the roller shaft of the cord-winding device has a set of stop rings extending at both sides thereon.  
     
     
         4 . The window blind structure as claimed in  claim 1  wherein the head rail is equipped with an accommodating channel indented therein, and a U-shaped insert groove cut at one outer side thereon for the inserting location of the positioning seat therein.  
     
     
         5 . The window blind structure as claimed in  claim 4  wherein the accommodating channel of the head rail thereof has an end opening defining both end edges thereon for the coupling of a matched sealing cover therewith respectively.  
     
     
         6 . The window blind structure as claimed in  claim 1  wherein each of the left/right drive-control pulley assemblies includes a positioning bi-pulley composed of a set of inner and outer rollers, and a guiding pulley that are symmetrically mounted at both ends of the head rail therein, permitting both positioning bi-pulleys of the left/right drive-control pulley assemblies to situate at the outer side of both guiding pulleys thereof respectively.  
     
     
         7 . The window blind structure as claimed in  claim 1  wherein a second beaded-chain control unit equipped with an operating cord can also be mounted to the other end of the head rail opposite to the first beaded-chain control unit thereof.  
     
     
         8 . The window blind structure as claimed in  claim 7  wherein the actuating cord of the first beaded-chain control unit and the operating cord of the second beaded-chain control unit are respectively linked to a plurality of pull cords and lift cords, and a middle rail is attached to the top edge of the blind body for the fixing of the lift cords thereto while the pull cords thereof are attached to the bottom rail so as to provide a two-stage and double-cord operated blind structure thereby.  
     
     
         9 . The window blind structure as claimed in  claim 1  wherein the left/right drive-control pulley assemblies can also have an auxiliary pulley mounted to situate at one side of the guiding pulley respectively.  
     
     
         10 . The window blind structure as claimed in  claim 1  wherein the through holes of the positioning seat thereof can be made in a rectangular shape.