Block and tackle window balance with bottom guide roller

A block and tackle window balance device comprising:

• a channel;
• a bottom guide located on the channel, the bottom guide comprising a substantially vertical portion adapted to guide the balance device along a rear wall of a window jamb surface when installed in a window jamb;
• and
• a guide roller rotatably mounted relative to the channel, at least a portion of the guide roller located below the substantially vertical portion when installed in a window jamb.

A block and tackle window balance device comprising:

• a channel comprising a bottom end;
• a bottom guide located on the channel;
• a guide roller rotatably mounted proximate the bottom end;
• a fixed pulley block unit located within the channel;
• a translatable pulley block unit moveable within the channel;
• a spring comprising a first end and a second end, wherein the first end is fixed relative to the channel and the second end is connected to the translatable pulley block unit;
• and
• a cord comprising a first cord end and a second cord end, wherein the cord is threaded through the translatable pulley block unit and the fixed pulley block unit and extends around the guide roller, the first cord end being attached to the translatable pulley block unit and the second cord end being attachable to a jamb, wherein the spring creates a tension force in the cord to secure the guide roller proximate the bottom end of the channel, when installed in a window jamb.

A block and tackle window balance device comprising:

• a channel comprising a top end and a bottom end;
• a top guide located proximate the top end, the top guide adapted for guiding a sash when installed;
• a bottom guide comprising a top end, the bottom guide located proximate the bottom end of the channel, the bottom guide adapted for guiding a sash when installed;
• and
• a bottom roller located proximate the bottom end of the channel, wherein at least a portion of the bottom roller is located below the top end of the bottom guide.