Patent ID: 7297064

Claim:
A torsional vibration damper, comprising: a first component turnable about a predetermined axis; a second component tumable about said axis with and relative to said first component; and at least one elongated compressive coil spring interposed between said components and arranged to oppose turning of said components relative to each other, said at least one coil spring having a first end portion bearing upon a first retainer turnable with said first component and a second end portion reacting against a second retainer turnable with said second component wherein the at least one coil spring has a length that is subdivided into at least two different sections, and wherein the at least two different sections respectively comprise at least one first set of convolutions with first outer diameters and at least one second set of convolutions with second outer diameters, said second outer diameters being constant over said at least one second set and said first diameters being smaller than said second diameters, and wherein the at least one coil spring is constrained in a centrifugal direction through slide elements at least in individual locations within the torsional vibration damper, said slide elements having flank portions extending at least partially along the at least one first set of convolutions, wherein each of the convolutions of said at least one first set and said at least one second set has a radially innermost portion relative to said predetermined axis, and wherein said radially innermost portions are located at substantially equal radial distances from said predetermined axis, and wherein all of the windings have the same cross-sectional wire profile, wherein the at least one coil spring in a stress-free state has an arcuate shape that curves over the length of the coil spring.