Spring motor and drag brake for drive for coverings for architectural openings

A spring motor and drag brake combination, comprising:

• an output spool mounted for rotation in clockwise and counterclockwise directions;
• a motor spring wound upon itself and defining a first end and a second end, said first end secured to said output spool;
• and
• a brake, including
• a housing;
• a brake drum functionally connected to said output spool such that rotation of said output spool results in rotation of said brake drum;
• a coil spring assembly mounted onto said brake drum by mounting means which cause said coil spring assembly to resist rotation of said brake drum relative to said housing in both the clockwise and counterclockwise directions, with the torque required to overcome the resistance to rotation being greater in one of said directions than in the other, said coil spring assembly including first and second coil springs mounted onto said brake drum, each of said first and second coil springs including a first end secured to said housing, wherein said first coil spring collapses onto said brake drum when said output spool rotates in one of said clockwise and counterclockwise directions and wherein said second coil spring collapses onto said brake drum when said output spool rotates in the other of said clockwise and counterclockwise directions.

A covering system for covering an architectural opening, comprising:

• a movable covering;
• a spring motor operatively connected to said movable covering, said spring motor including an output spool and a flat spring having a first end and a second end, said flat spring being connected to said output spool at said first end, wherein at least one portion of the flat spring which is farther away from said first end has a coil set with a larger radius of curvature than a second portion of the flat spring which is closer to said first end and has a coil set with a smaller radius of curvature and wherein said output spool is mounted for rotation in clockwise and counterclockwise directions;
• a brake drum functionally connected to said output spool such that rotation of said output spool results in rotation of said brake drum;
• a housing;
• and
• a coil spring assembly mounted onto said brake drum by mounting means which cause said coil spring assembly to resist rotation of said brake drum relative to said housing in both the clockwise and counterclockwise directions, with the torque required to overcome the resistance to rotation being greater in one of said directions than in the other;
• wherein said housing is stationary and defines an inner bore;
• wherein said coil spring assembly includes a smaller diameter spring portion and a larger diameter spring portion, wherein said smaller diameter spring portion collapses onto said brake drum and said larger diameter spring portion contracts away from said inner bore when said brake drum rotates in one of said clockwise and counterclockwise directions, and wherein said smaller diameter spring portion expands away from said brake drum and said larger diameter spring portion expands against said inner bore when said brake drum rotates in the other of said clockwise and counterclockwise directions.