Controller assembly for window blind apparatus

A controller assembly for a first drive shaft and a second drive shaft, said controller assembly comprising:

• a housing including a left wall and a right wall which is spaced apart from said left wall in a left-right direction, each of said left and right walls having a first through bore and a second through bore;
• a first tube unit having a first outer threaded surface, and rotatably retained in said housing, said first tube unit being coupled to be driven by the first drive shaft to rotate about a first axis which extends in the left-right direction, said first tube unit including
• a first left tubular stem configured to be rotatably received in said first through bore of said left wall,
• a first right tubular stem configured to be rotatably received in said first through bore of said right wall,
• a first screw tube disposed between said first left and right tubular stems, and having said first outer threaded surface,
• a first left outer flange provided between said first left tubular stem and said first screw tube to prevent insertion of said first screw tube into said first through bore of said left wall, and
• a first right outer flange provided between said first right tubular stem and said first screw tube to prevent insertion of said first screw tube into said first through bore of said right wall;
• a second tube unit having a second outer threaded surface, and rotatably retained in said housing, said second tube unit being spaced apart from said first tube unit in a front-rear direction, and being coupled to be driven by the second drive shaft to rotate about a second axis which extends in the left-right direction, said second tube unit including
• a second left tubular stem configured to be rotatably received in said second through bore of said left wall,
• a second right tubular stem configured to be rotatably received in said second through bore of said right wall,
• a second screw tube disposed between said second left and right tubular stems, and having said second outer threaded surface,
• a second left outer flange provided between said second left tubular stem and said second screw tube to prevent insertion of said second screw tube into said second through bore of said left wall, and
• a second right outer flange provided between said second right tubular stem and said second screw tube to prevent insertion of said second screw tube into said second through bore of said right wall;
• a first runner having a first inner threaded bore which is configured to be in threaded engagement with said first outer threaded surface of said first tube unit, said first runner being retained to slide along the first axis when said first tube unit is driven to rotate about the first axis;
• a second runner having a second inner threaded bore which is configured to be in threaded engagement with said second outer threaded surface of said second tube unit, said second runner being retained to slide along the second axis when said second tube unit is driven to rotate about the second axis, said first and second runners being configured to be brought into abutment with each other in the left-right direction,
• such that in response to leftward sliding of said first runner to bring said first runner into abutment with said second runner, said first runner is prevented from sliding leftward over said second runner, whilst impeding rotation of said first tube unit, and
• such that in response to rightward sliding of said second runner to bring said second runner into abutment with said first runner, said second runner is prevented from sliding rightward over said first runner, whilst impeding rotation of said second tube unit;
• a first biasing spring disposed in said first through bore of said right wall to bias said first right outer flange away from said right wall;
• and
• a second biasing spring disposed in said second through bore of said left wall to bias said second left outer flange away from said left wall,
• wherein said first runner is formed with a first stop tab which has a leftward abutment surface, and said second runner is formed with a second stop tab which has a rightward abutment surface, said leftward and rightward abutment surfaces being configured to be brought into abutment with each other in the left-right direction when said first and second runners are in abutment with each other;
• wherein said first tube unit further includes a first locked peg provided on a right surface of said first right outer flange, and a first locking pin is provided inside said housing on said right wall,
• such that when said leftward abutment surface is spaced apart from said rightward abutment surface in the left-right direction, said first locked peg is biased by said first biasing spring to be disengaged from said first locking pin, thereby permitting said first tube unit to rotate relative to said housing, and
• such that once said first runner is moved to bring said leftward abutment surface into abutment with said rightward abutment surface, said first tube unit is permitted to move rightward against a biasing force of said first biasing spring to bring said first locked peg into locking engagement with said first locking pin so as to further impede rotation of said first tube unit;
• and
• wherein said second tube unit further includes a second locked peg provided on a left surface of said second left outer flange, and a second locking pin is provided inside said housing on said left wall,
• such that when said leftward abutment surface is spaced apart from said rightward abutment surface in the left-right direction, said second locked peg is biased by said second biasing spring to be disengaged from said second locking pin, thereby permitting said second tube unit to rotate relative to said housing, and
• such that once said second runner is moved to bring said rightward abutment surface into abutment with said leftward abutment surface, said second tube unit is permitted to move leftward against a biasing force of said second biasing spring to bring said second locked peg into locking engagement with said second locking pin so as to further impede rotation of said second tube unit.