Helical extension springs store energy and exert a pulling force. Extension springs differ from compression springs in that they do not have a solid stop to prevent overloading. For this reason, they are designed with lower stress levels. Typical applications include balance scales, trampolines, garage doors, dock levelers, farm machinery and various types of spring tensioning devices. Extension springs come in a wide array of sizes from small medical devices to off-road machinery brake springs.
In order to be a part of an assembly, extension springs require a method of attachment. Threaded inserts, swivel hooks, twisted loops and side loops are just a few of the nearly limitless options available. At the design stage, the length and positioning of the hooks at each end of the spring can be adjusted in order to obtain exactly the required spring load at any extended position. Silencers can be used to prevent vibration within the spring itself as well as eliminating noise in the application without upsetting the function of the spring.
Peterson Spring specializes in extension springs, using state of the art machinery and world class engineering. Our corporate laboratory, as well as individual plant testing facilities, allow us to fully serve every customer with superior manufacturing, testing data, and metallurgical documentation.
Check out the latest article on Peterson Spring in the Spring Manufacturers Institute (SMI) "Springs" Magazine.