Patent · US Expired

Fatigue and damage tolerant coil spring

US6811149B1 · kind B1 · utility

7Cited by
10References
2Claims
0Family size

Inventor

Key dates

Filing dateOct 27, 2003
Grant dateNov 2, 2004
Priority date
Expiry dateOct 27, 2023

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/479
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

Predetermined non-uniform residual compressive stress distributions are induced in the spring wire of metallic coil springs. The residual compressive stress tends to reduce deleterious effects of both fatigue and coil binding impacts on spring performance. Transverse cross-sections of coil spring wire reveal non-uniform distributions of residual compressive stress that exhibit substantial symmetry about various transverse axes, including axes connecting potential or actual opposing coil binding contact points on the spring wire surface. Residual compressive stress in coil spring wire of the present invention may also vary in a predetermined manner when measured longitudinally along the coil spring wire.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.