Semi-rigid chain assembly

An apparatus for rotating a roller tube of a window treatment to raise and lower a covering material, the apparatus comprising:

• a drive element configured to rotate the roller tube to raise and lower the covering material of the window treatment;
• and
• a chain assembly operatively coupled to the drive element for rotating the roller tube, the chain assembly including a hollow chain having a plurality of links forming a loop, and a rod located within the hollow chain, wherein the hollow chain is configured to surround and operate along the rod, such that the hollow chain is operable to move relative to the rod.

An apparatus for rotating a roller tube of a window treatment to raise and lower a covering material, the apparatus comprising:

• a drive element configured to rotate the roller tube to raise and lower the covering material of the window treatment;
• and
• a chain assembly operatively coupled to the drive element for rotating the roller tube, the chain assembly including a flexible member forming a loop, and a rigid member having a curved portion, wherein the rigid member is configured to define a size of a fixed radius of the curved portion, and wherein the rigid member is disposed within a hollow space defined by the flexible member and the flexible member is configured to operate along the rigid member, such that the flexible member is operable to move relative to the rigid member.