Patent ID: 7331434

Claim:
An impact absorber for absorbing impact forces including absorbing forces in case of a collision of a motor vehicle with an obstacle, the impact absorber comprising: an inner tube with a closed bottom plate; an outer tube having opposite first and second open ends, said inner tube being positioned to be pushed into said first open end of said outer tube in a telescopic manner, an end of said inner tube with said closed bottom plate comprising a free end projecting from said outer tube; a wall displaceable in said inner tube, said inner tube and said wall cooperating to form, a gas space filled with pressurized gas, followed in a direction of a longitudinal axis by a first fluid-filled liquid space separated from said gas space by said wall and a second fluid-filled liquid space; a throttle element, said second fluid-filled liquid space being in fluid communication with said first fluid-filled space through said throttle element; and a piston arranged in an interior of said outer tube and fixed in a liquid-tight manner relative to an inner wall of said outer tube towards said second open end of said outer tube, said second fluid-filled space adjoining said first fluid-filled space in a direction of said longitudinal axis and being closed by said piston, said throttle element comprising an integral part of said piston and said second fluid-filled space being arranged in a ring-shaped pattern between said inner wall of said outer tube and said outer wall of said piston, said piston being formed from a plastic.