Retractable window shade with multiple shading gradations

Abstract

A retractable window shade with multiple shading gradations has a guide rail, two shade bodies and two cord assemblies. The guide rail has two one-way arresting mechanisms. The two shade bodies have different opacities and each shade body has a top side mounted on the guide rail and a lower section. The cord assembles are respectively mounted through the one-way arresting mechanism and connected to the lower sections of the of the shade bodies. The cord assemblies are pulled to rise the lower sections of the shade bodies. When the force for pulling one shade body is released, the cords are selectively arrested by the one-way arresting mechanisms to hold the shade body in a proper position. By expanding both of, one of or none of the shade bodies, the retractable window shade provides a proper proportion of shading sunlight with appropriate, comfortable and mild brightness.

1 . A retractable window shade with multiple shading gradations comprising:
 a guide rail ( 30 ) having a bottom, two ends, two one-way arresting mechanisms ( 60 ), two major holes ( 31 ) formed through the bottom of the guide rail ( 30 ) at an interval and two secondary holes ( 32 ) formed through the bottom of the guide rail ( 30 ) at an interval;   a major shade body ( 10 ) retractably mounted on the guide rail ( 30 ) and having an opacity, a top side mounted on the guide rail ( 30 ), a bottom side and a lower section;   a major cord assembly ( 40 ) having two major cords ( 41 ), each of the major cords ( 41 ) having a distal end and a proximal end, the proximal ends of the major cords ( 41 ) being mounted through one of the one-way arresting mechanisms ( 60 ), respectively extending through the major holes ( 31 ) and connected to the lower section of the major shade body ( 10 );   a secondary shade body ( 20 ) retractably mounted on the guide rail ( 30 ) and has an opacity lower than that of the major shade body ( 10 ), a top side mounted on the guide rail ( 30 ), a bottom side, a lower section; and   a secondary cord assembly ( 50 ) having two secondary cords ( 51 ), each of the secondary cords ( 51 ) having a distal end and a proximal end, the proximal ends of the secondary cords ( 51 ) being mounted through the other one of the one-way arresting mechanisms ( 60 ), respectively extending through the secondary holes ( 32 ) and connected to the lower section of the secondary shade body ( 20 ).   
     
     
         2 . The retractable window shade with multiple shading gradations as claimed in  claim 1 , wherein
 the guide rail ( 30 ) further has two mounting holes ( 33 ) formed through the bottom of the guide rail ( 30 ) respectively near the ends of the guide rail ( 30 );   the one-way arresting mechanisms ( 60 ) are mounted respectively in the mounting holes ( 33 ) and each of the one-way arresting mechanisms ( 60 ) having
 a housing ( 61 ) having
 an open top ( 611 ); 
 an open bottom ( 612 ); 
 a guide rod ( 614 ) mounted transversely in the housing ( 61 ); and 
 an oblique sidewall ( 613 ) inclining downward and having multiple one-way teeth; 
 
 a retain member ( 62 ) mounted longitudinally through the housing ( 61 ) near the open bottom ( 612 ) of the housing ( 61 ); and 
 an one-way ratchet ( 63 ) mounted in the housing ( 61 ) and selectively engaged with the one-way teeth of the oblique sidewall ( 613 ) of the housing ( 61 ); 
   the proximal ends of the major cords ( 41 ) extend through the open top ( 611 ), the guide rod ( 614 ) and the open bottom ( 612 ) of a corresponding one-way arresting mechanism ( 60 ) in turn and selectively press the one-way ratchet ( 63 ) of the corresponding one-way arresting mechanism ( 60 ) to engage with the oblique sidewall ( 613 ) of the housing ( 61 ) of the corresponding one-way arresting mechanism ( 60 ); and   the proximal ends of the secondary cords ( 51 ) extend through the open top ( 611 ), the guide rod ( 614 ) and the open bottom ( 612 ) of a corresponding one-way arresting mechanism ( 60 ) in turn and selectively press the one-way ratchet ( 63 ) of the corresponding one-way arresting mechanism ( 60 ) to engage with the oblique sidewall ( 613 ) of the housing ( 61 ) of the corresponding one-way arresting mechanism ( 60 ).   
     
     
         3 . The retractable window shade with multiple shading gradations as claimed in  claim 2 , wherein the retain member ( 62 ) of each arresting mechanism ( 60 ) further has a retain section ( 621 ) bent downward and mounted in the housing ( 61 ) of the arresting mechanism ( 60 ). 
     
     
         4 . The retractable window shade with multiple shading gradations as claimed in  claim 1 , wherein
 the major shade body ( 10 ) further has
 a bottom bar ( 11 ) mounted longitudinally on the bottom side of the major shade body ( 10 ); 
 multiple sleeves ( 12 ) woven sequentially on the major shade body ( 10 ) at intervals to divide the major shade body ( 10 ) into multiple plaits ( 15 ); and 
 multiple slats ( 13 ) mounted respectively and longitudinally in the sleeves ( 12 ); and 
   the proximal ends of the major cords ( 41 ) are connected to one of the sleeves ( 12 ) of the major shade body ( 20 ).   
     
     
         5 . The retractable window shade with multiple shading gradations as claimed in  claim 4 , wherein
 each of the sleeves ( 12 ) of the major shade body ( 10 ) in an even sequence is an even sleeve ( 12 ) and has two limiting rings ( 14 ) mounted on the even sleeve ( 12 ) at an interval corresponding to the interval between the major holes ( 31 ); and   the proximal ends of the major cords ( 41 ) are connected respectively to the limiting rings ( 14 ) of a lowermost even sleeve ( 12 ) of the major shade body ( 10 ) through the limiting rings ( 14 ) of intervening even sleeves ( 12 ).   
     
     
         6 . The retractable window shade with multiple shading gradations as claimed in  claim 5 , wherein
 the secondary shade body ( 20 ) further has
 a bottom bar ( 21 ) mounted longitudinally on the bottom side of the secondary shade body ( 20 ); 
 multiple sleeves ( 22 ) woven sequentially on the secondary shade body ( 20 ) at intervals to divide the secondary shade body ( 20 ) into multiple plaits ( 25 ); and 
 multiple slats ( 23 ) mounted respectively and longitudinally in the sleeves ( 22 ); and 
   the proximal ends of the secondary cords ( 51 ) are connected to one of the sleeves ( 22 ) of the secondary shade body ( 20 ).   
     
     
         7 . The retractable window shade with multiple shading gradations as claimed in  claim 6 , wherein
 each of the sleeves ( 22 ) of the secondary shade body ( 20 ) in an even sequence is an even sleeve ( 22 ) and has two limiting rings ( 24 ) mounted on the even sleeve ( 22 ) at an interval corresponding to the interval between the major holes ( 31 ); and   the proximal ends of the secondary cords ( 51 ) are connected respectively to the limiting rings ( 24 ) of a lowermost even sleeve ( 22 ) of the secondary shade body ( 20 ) through the limiting rings ( 24 ) of intervening even sleeves ( 22 ).   
     
     
         8 . The retractable window shade with multiple shading gradations as claimed in  claim 7 , wherein
 the major cord assembly ( 40 ) further has two grips ( 42 ) mounted respectively at the distal ends of the major cords ( 41 ); and   the secondary cord assembly ( 50 ) further has two grips ( 52 ) mounted respectively at the distal ends of the major cords ( 51 ).