Semi-cordless unbalanced spring driven blind system and methods for adjusting and making same

A horizontal window blind comprising:

• a head rail;
• a shaft extending through the head rail;
• a plurality of slats with a lifting material;
• a gathering member coupled to the shaft to receive and wind the lifting material;
• a gear box engaged to the shaft;
• a torsion spring with one end engaged to the gear box and the opposing end engaged to the head rail to provide a continuous lifting force to lift the slats and coil the lifting material on the gathering member, the gear box being arranged to reduce the rotation ratio between the shaft and the torsion spring;
• a releasable brake with a brake arm and drum on the shaft cooperating to define a first position in which the brake prevents the rotation of the shaft by pivoting the brake arm against the brake.

A method for the assembly of an unbalanced horizontal blind or window treatment to have a continuous retraction force comprising the steps of:

• providing the components of a window treatment, the components comprising (a) a spring with a drum and tab for winding, (b) a plurality of stats or a cover, (c) a flexible lifting material, and (d) a head rail;
• providing a winding strap of a pre-determined length;
• attaching the winding strip to the tab;
• winding the winding strap onto the drum;
• assembling the components of the window treatment with the spring disposed in the head rail such that the spring can rotate;
• winding the flexible lifting material to gather the cover or slats to the head rail;
• securing one side of the spring while unwinding the winding strip to preload a force into the spring;
• and
• coupling the spring to the head rail to maintain the force loaded into the spring.

A window treatment system comprising:

• a shaft;
• a length of flexible lifting material;
• a gathering member coupled to the shaft to receive and wind the lifting material;
• a window cover combined with the lifting material to permit the window cover to lift with the movement of the lifting material toward the shaft;
• a spring coupled to the shaft and being pre-loaded to provide a continuous retraction force for lifting the cover and coiling the lifting material by the gathering member;
• and
• a brake coupled to the shaft to selectably permit or prevent rotation of the shaft.

A horizontal window blind comprising:

• a head rail;
• a shaft disposed in the head rail;
• a length of flexible lifting material;
• a length of flexible ladder material;
• a plurality of slats combined with the lifting material and the ladder material to permit the slats to lift with the movement of the lifting material;
• a gathering means coupled to the shaft to receive and wind the lifting material;
• a spring means coupled to the shaft and head rail to provide a continuous retraction force for lifting slats and coiling the lifting material by the gathering means;
• a tilter coupled to the shaft and the ladder material;
• a tilting control to operate the tilter to tilt the slats;
• and
• a brake coupled to the shaft to selectably permit or prevent rotation of the shaft.