Abstract: A block shaped to fit onto an end of a block and tackle window balance containment tube which controls excessive airflow into and out of the jamb channel of the window frame to assist with the insulating function of the window frame and to substantially prohibit the accumulation of dirt and dust within the balance containment tube. The block is secured to the end of the balance containment tube by a rigid or semi-rigid retainer. The block itself may consist of either a pliable or rigid material.

Abstract: The invention relates to a connector element to be used with curtain rails having a substantially inverted U-shaped cross-section with its legs being flanged inwards, said flanged legs at the bottom defining a longitudinal extending opening at both sides limited by raised supporting edges formed by the extremities of the flanged legs, for supporting curtain sliders. The connector element provides for a coupling of subsequent lengths of curtain rail in which it is provided for that at the transition, the curtain sliders project beyond the supporting edge and are forced to the middle, as a result of which the otherwise occurring shocking movement at the transition between abutting extremities of lengths of curtain rail is prevented.

Abstract: An improved window sash balance and components thereof. The balance includes a spring fixed with respect to the frame and a pair of pulley blocks, each containing one or more pulleys. One block is fixed with respect to the frame and the other is disposed on the end of the spring. A cord is secured to one pulley block and trained over the pulleys. The other end of the cord terminates in a hook adapted to be received in an opening in the window jamb channel. The pulley block unit includes a pulley-receiving frame, one, two or three pulleys received therein, and at least one axle for rotatably supporting the pulleys within the frame. The block has one or two pulley-receiving openings therein, and suitable openings for reception and positioning of the axle. The block includes first and second pairs of assembly reference surfaces forming a part of the block and spaced radially from the axle opening.