(57) The present invention relates to a self-raising window covering and a control mechanism
for the window covering. In particular, the window covering (38) includes a drive
unit (14), such as constant force spring, that is adapted to apply a substantially
constant rotational force on the drive axle. A cord winding assembly (20,22) is coaxially
mounted on the drive axle, and includes at least one winding drum (24,26) operatively
connected to a second end of the raising cord and having a tapered portion, as well
as a rotatable positioning member (32) for moving the cord winding assembly laterally
along the drive axle upon rotation of the positioning member. The cord winding assembly
is adapted to translate the rotational force on the drive axle to a raising force
on the raising cord, wherein the raising force is greater than a downward force exerted
by the shade element and bottom rail throughout the range of opening and closing.
A clutch member or locking member is also operatively connected with the axle and
adapted to releasably lock the drive axle in a desired position.
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