5 Problems to Avoid When Designing a Power Spring.


The 5 Biggest Problems in Power and Conpower® Spring Design and How to Avoid Them.

Our customers are creative and often come up with unique problems they want to solve using springs.  We enjoy working on these situations as it fully utilizes our team’s experience and skill to push our limits and keep us charging forward.   However, even with all of our experience and design capability, we must live with some fixed rules of physics and mechanical design regarding our springs.  We will discuss here several traps that our customers sometimes fall into, specifically in the power spring segment.     

Before we get to the list, let’s review the basics.  Traditional power springs and Conpower® springs are manufactured with strips of spring steel to provide torque.  Spring steel is a low-alloy, medium-carbon steel or high-carbon steel with a very high yield strength. Objects made of spring steel can return to their original shape despite significant bending or twisting. 

A “power” spring is wound with flat (non-stressed) steel, while a “Conpower®” spring uses pre-stressed steel to generate a larger usable torque range than a traditional power spring. Vulcan primarily manufactures the Conpower® version due to its advantages over power springs.  Conpower® springs ramp up faster to usable torque, are smaller, lighter, have longer range (turns), don’t require as much lubrication, and are significantly smoother in operation.

During manufacturing, the spring is wound into either a retaining ring or customer's housing (retaining ring shown to the right). When ready for final installation, the spring is carefully inserted into its case with the outside end secured to the outer edge and the inside end attached to an arbor (see illustration below).   During operation, either the case or the arbor will be fixed while the other component is left free to rotate.  Depending on the requirements of your specific design, it may be beneficial to use a fixed arbor/free case or free case/fixed arbor arrangement.        

These springs are often used to retract a cord or cable around a spool.  You might find one in your lawnmower, a retractable lanyard or dog leash.  This is also the type of spring used to drive a number of mechanical clocks and timers, which is why they are sometimes referred to as “clock springs.” 

The load that the springs provide grows with the cross-sectional area of the material.  The number of turns the spring can provide is determined from the space available between the arbor and the case ID along with the total length of the spring.  All  Conpower® springs require pre-winding from their free state in order to reach their effective working range.  More general background information can be found on our Conpower® and power spring page or our previous blog.

In power spring, conpower, conpower spring

5 Steps to Designing a Custom Security Tether


Generate Sales by Enhancing Customer Experience with a Custom Pullbox®.

The Pullbox, the original security tether, is ideal for retail store display product positioning and as a product sample theft deterrent. Display security tethers can be purchased as stock but at Vulcan Spring, the inventor of the Pullbox, we understand that every project is unique and has its own set of requirements.  By utilizing a custom Pullbox, you can tailor the experience for a customer, resulting in a thrilled buyer and ultimately more sales. Everybody wins!

In Pullbox

POP Quiz for Point-of-Purchase

It’s back to school time again and since our last Back to School Quiz was so popular, we thought it was time for another one! Take a short break from your day and give your brain a boost with our new POP Quiz for the point-of-purchase product lines. Don’t forget to let us know how you did!

In POP, Point-of-Purchase, quiz, pop quiz, display products