Introduction
High start power springs are custom-manufactured components designed to provide near-constant torque in compact spaces. They are ideal for applications such as seat belt retraction, tape measure retraction, and window recliners. These springs are a superior alternative to conventional clock springs when a greater number of turns or constant torque is required.

Specifications and Design
Typically, a high start retractor spring can exceed 100,000 cycles of fatigue life, depending on the design. The spring consists of a hook profile secured to a housing and an arbor integrated into the application’s spool. The arbor rotates to wind the spring as the device's webbing or tape is extracted, and the spring retracts the webbing when released.

Assembly and Pre-tensioning
Springs are generally supplied fitted inside the customer's housing. If impractical, they can be provided in a retaining ring or as a raw spring for customer assembly. Pre-tensioning the spring is possible with suitable design, simplifying the assembly process.

Operational Guidelines
While springs may have more than 20 turns, only about 12 are safe for operation. Initial and final turns should not be used due to inconsistent torque, which can lead to premature fatigue failure. A Spiroflex Sales Engineer can identify the safe working area and recommend the number of pre-turns.

Health & Safety Warning
Springs in keeper rings or housings must be handled with care as they are unstable until assembly is complete. Mishandling can cause them to eject forcefully, potentially causing injury. Consult a Spiroflex Sales Engineer for handling advice.

Conclusion
For specific requirements, contact a Spiroflex Sales Engineer to develop a product tailored to your needs. Typical torque profiles and spring values are available upon request.