Window sash counterbalance with independently operable sashes

A hybrid sash counterbalance and assist operated window with independently operable sashes comprising:

• a window frame having upper and lower sashes slideable within the window frame;
• first and second guides coupled with the window frame;
• a sash coupling element extending between the upper and lower sashes and movably coupled along the first and second guides;
• and
• a hybrid sash counterbalance and assist mechanism coupled with the sash coupling element, the hybrid sash counterbalance and assist mechanism includes:
• an intermediate pulley movably coupled along the sash coupling element,
• a block and tackle, a flexible tackle element of the block and tackle includes first and second tackle element ends, the first tackle element end is coupled to the block and tackle, and the second tackle element end is coupled to the intermediate pulley, and
• a spring coupled between the window frame and the block and tackle.

A method of counterbalancing and independently operating a window comprising:

• counterbalancing movement of a first sash with opposed movement of a second sash, wherein the first and second sashes are coupled with a flexible sash coupling element, and the sash coupling element is coupled with a hybrid sash counterbalance and assist mechanism;
• and
• independently moving one of the first or second sashes from the other of the second or first sashes, independently moving including:
• retaining the second sash in a static location or moving the second sash in a first direction,
• moving the first sash from the second sash in the first direction while the second sash is retained in the static location or moved in the first direction, and
• assisting the movement of at least the first sash with the hybrid sash counterbalance and assist mechanism.