Spring-like material formed of compressed metallic wire

Claim 1

A resilient and durable metallic material for supporting loads and accommodating motions within a preselected range of magnitudes, comprising: a substantially homogeneous mass of drawn metallic wires extending in substantially random relationship to each other; said wires having a predetermined density and high tensile strength, and the diameter thereof being within the range of 0.0035 inch to 0.020 inch; said wires as initially incorporated within said mass including three-dimensional helical coils spaced along the length thereof at pitch intervals within the range of 0.05 to 0.30 inch and having diameters at least ten times the wire diameter and within the range of 0.05 inch to 0.30 inch; said mass of coil-containing wires being compacted, by a compression force greater than the maximum force to be applied to the material during use, to impart thereto a preselected shape and a density within the range of 10 percent to 50 percent of said predetermined density; said wires being substantially free of stress risers other than ones produced by the compaction of mass; the compression stress/strain properties of said compacted mass being in accordance with the relationship σ≦500 (200.sup.3.3ε) and ≧1000.sup.1.25ε for values of ε from 0 to 0.50, wherein σ is stress in psi and ε is strain in inches per inch, and said properties being substantially isotropic at strain levels of from 0 to 0.20.