Counterbalance with Constant Force Springs

Posted by Catherine Tyger on Wed, Oct 10, 2012 @ 10:00 AM

In constant force springs, Conforce®, constant force, engineering, counterbalance, counterbalancing

Constant Force Springs are commonly used to provide a counterbalance effect for a product.  This blog examines different ways to integrate a counterbalance into a design, emphasizing the use of constant force springs in the manufacturing of a counterbalanced unit.

Counterbalance, as defined in Webster’s Dictionary states:

  1. a weight that balances another

  2. a force or influence that offsets or checks an opposing force

counterbalance drawing 1As stated in the first definition, when one weight balances another, it shows the characteristics of a counterbalance.  In one option, a weight of equal mass is arranged to offset the weight of the component part.  The diagram to the right shows that this is usually accomplished using a pulley system, a cable and a weight.

In this design, the overall weight of the product will be increased by 5 pounds due to the addition of the counterbalance weight. Extra space is also required in order to accommodate the system.

counterbalance drawing 2A constant force spring can be used in place of the weight system and is an example of the second definition of counterbalancing, which is a force or influence that offsets or checks an opposing force.  Using Vulcan Spring’s Conforce® spring for this application will greatly reduce the added weight and space required to counterbalance the component.  Our stock spring, SH10K33 for example, would work for 28” of travel.  The weight of this spring is .07 pounds, which provides 5 pounds of force.  The outside diameter is approximately 1.00”. 

Other options, including a longer length of travel, can be customized to fit the application and requirements.  The mechanical spring assembly could look like the diagram to the left.

Constant force springs have many benefits over a generic weight system for counterbalancing, such as smaller space requirements and less overall weight.  For more information please visit our website.

Questions? Call us at 215-721-1721 – we’ll answer the phone!