This page contains a Flash digital edition of a book.
DESIGN COMPONENTS Springs, Gas Springs and Dampers

Getting ahead of the opposition

Retaining rings and wave springs used in athletic shoes are helping to reduce the stress on joints in demanding activities

lightweight design compared to conventional coil springs. Wave springs, which typically operate at half the height

F 18

of conventional coil springs, provide an accurate repeatable load in both the heel and ball of shoes. A single crest-to-crest wave spring in the heel and two parallel wave springs in the ball of the shoe absorb the impact associated with athletic activities, reducing stress on joints. Smalley flat wire wave springs from TFC were selected

for this application. The springs, manufactured in corrosion resistant 17-7 stainless steel, were specifically designed to handle the extensive cycle life that is associated with the wear of the shoes. Smalley wave springs offer accurate, repeatable loads for the duration of the spring life which is designed to outlast the life of the shoe itself. Using the same

lat wire wave springs are being used by shoe manufacturers for cushioning in the soles of both athletic and casual shoes. Wave springs are used because of their space saving abilities and

unique method of manufacture, TFC Spirolox retaining rings offer an ideal space saving alternative to conventional circlips. By ‘edge- coiling’ rectangular section material to exact dimensions, (rather than using the die-stamping process that is used to produce conventional circlips), Spirolox retaining rings have a uniform cross-section without lugs to interfere with the assembly and are free of burrs. With a wide range of sizes and materials to chose from, Spirolox rings can be found in thousands of mechanical products throughout the world. In an equally challenging application, a manufacturer of

pipeline recovery tools recently came to TFC for a spring that would operate in a 700mm bore, provide in excess of 12,000N force, but still be capable of offering over 200mm of travel – all within a radial cavity of around 200mm. The radial restraint prevented the use of pocketed coil springs or stacked disc spring sets. So TFC designed its biggest ever

Smalley crest-to-crest wave spring to do the job. Comprising 55 turns and with over 15 waves per turn, the wave spring was able to provide the necessary load and travel with a free height of less than 600mm. Crest-to-crest wave springs maintain the same force and

load specifications of a conventional round wire spring yet occupy 50% or less of the axial space, resulting in lowered operating heights, free heights and solid heights. Available in carbon steel, stainless steel and other exotic alloys, the method of manufacture does not require any expensive tooling. As a result, even low quantity custom designs can be produced quickly and economically.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52