Patent ID: 8979079
Filing Date: 2015-03-17
Classification: F16F,Y10T

Abstract:
1. A progressive spring coil, comprising: a first spring portion having a substantially conical shape defined by a plurality of convolutions having a first pitch, the first spring portion comprising a top end and a bottom end and having a first spring rate, wherein the first spring rate is substantially linear or substantially nonlinear, and wherein the top end has a diameter less than a diameter of the bottom end; a second spring portion having a substantially conical shape defined by a plurality of convolutions having a second pitch, the second spring portion comprising a top end and a bottom end and having a second spring rate, wherein the second spring rate is substantially linear or substantially nonlinear, and wherein the top end has a diameter larger than a diameter of the bottom end; and a third spring portion having a substantially cylindrical or a substantially hyperbolic shape disposed between the first spring portion and the second spring portion and defined by a plurality of convolutions having a third pitch, wherein the third spring portion has a third spring rate, and wherein the third spring rate is substantially linear or substantially nonlinear, wherein the first pitch of the first spring portion is less than the second pitch of the second spring portion and less than the third pitch of the third spring portion, and wherein the third spring portion further comprises a first transition loop disposed between the bottom end of the first spring portion and the third spring portion and a second transition loop disposed between the to end of the second spring portion and the third spring portion, wherein a pitch of the second transition loop is greater than the pitch of the first transition loop.