摘要 |
Resilient spring member for a roller skate, the member comprising a profile (1, 30, 40 and 50) with holes (2, 3, and 45) made of well-vulcanised rubber or well polymerised EPDM satured with peroxide or similar material that has a progressive growing stress to elongation ratio over its working limits, whereby its stiffness is increased by deformation and amplified by pulling. |