Patent ID: 8608142

Claim:
A device for absorbing kinetic energy of a moving body, comprising: a tension member which comprises a plastically deformable helical spring having a single stack of convolutions, the stack of convolutions having a first part including at least one convolution, an inner surface of the first part of the stack of convolutions defining a passage, the stack of convolutions having a second part including at least one convolution, each of the at least one convolution in the second part of the stack of convolutions having a diameter smaller than a diameter of the at least one convolution in the first part of the stack of convolutions and a pitch larger than a pitch of the at least one convolution in the first part of the stack of convolutions arising from deformation of the at least one convolution in the second part of the stack of convolutions relative to the at least one convolution in the first part of the stack of convolutions, at least a portion of the second part of the stack of convolutions being situated in the passage defined by the first part of the stack of convolutions; and stop means for retaining a position of the stack of convolutions, the stop means comprising a support that supports the first part of the stack of convolutions, the support including a through-hole communicating with the passage defined by the first part of stack of the convolutions, at least a portion of the second part of the stack of convolutions being situated in the through-hole in the support.