Block & Tackle Balances

Manufactured By Caldwell Since 1986

Caldwell’s block and tackle balances are a popular and growing platform. Long the standard for wood window designers, block and tackle balances are now incorporated into aluminum, vinyl and composite material windows.

Our block and tackle is a versatile balance platform with versions that support both tilt and sideload window designs. No other balance platform provides such a well-adopted solution for sideload window types.

Recently, Caldwell’s inverted block and tackle tilt balance has gained market share because it travels with the sash and is hidden from view. This type of block and backle Balance allows the sash to be opened 100%.

How Block and Tackle Balances Work

Caldwell’s Block and Tackle Balance is an assembly of:

  • A rigid steel channel
  • One or more steel extension spring
  • Fixed and traversPulleys
  • Braided polyester cord­

Block and tackle balances use extension spring force to counterbalance the weight of a window sash. The arrangement of the pulleys and cord provide a 5:1 travel characteristic. This means that the sash can travel 5 times the total spring extension. When the spring is fully extended (like it would be in a closed lower sash) the spring force provides maximum life assistance.

Benefits of Block and Tackle Balances
Caldwell has continued to develop innovations to our block and tackle balance to provide simpler window assembly and quick methods of field service.

  • Attached carriers allow for easy replacement of the balance after the vinyl window frame extrusions have been welded.
  • Easy application method simplifies and improves productivity on the factory floor.
  • Replacement process is quick and inexpensive.
  • Wide range of available accessory parts allows for easy installation of sash
  • Rigid channel improves structural integrity of the window.