Patent ID: 7063181

Claim:
A method of using a power steering fluid hose for dampening fluid-borne noise in automotive power steering system which comprises the steps of: (a) directing power steering fluid through a power steering fluid hose having a laminated inner tube surrounded by a reinforcing outer tube, (b) selecting the materials and radial thickness dimensions of said laminated inner tube to provide a resilient inner layer having good noise dampening properties with a radial thickness T 1 and a resilient outer layer with a radial thickness T 2 and having lesser noise dampening characteristics than said inner layer but capable of providing hoop strength reinforcement under adverse high temperature conditions, (c) selecting said inner layer material to have a softer durometer value than said outer layer (d) bonding said inner layer by vulcanization to said outer layer, and (e) selecting by empirical determination a ratio of said radial thicknesses T 1 and T 2 found to maximize dampening of fluid-borne noise in said system within a preselected frequency range by elastic radial expansion of said inner and outer layers.