Patent ID: 7441817

Claim:
A trailer crash attenuation assembly comprising: a first longitudinal hollow member, a portion at one end of said first longitudinal hollow member adapted to act as a hydraulic cylinder, said portion having a relatively small orifice; hydraulic fluid disposed in said hydraulic cylinder; a tank fluidly coupled to said relatively small orifice in said first longitudinal hollow member; a first longitudinal telescopic member adapted to slide into and out of said first longitudinal hollow member, said first longitudinal telescopic member adapted to act as a piston within said hydraulic cylinder; second and third longitudinal hollow members positioned substantially parallel to and on either side of said first longitudinal hollow member, said second and third longitudinal hollow members connected to said first longitudinal hollow member; second and third longitudinal telescopic members adapted to slide into and out of said second and third longitudinal hollow members respectively; a casing connected at its proximal end to said first, second and third longitudinal hollow members, said casing adapted at its distal end to receive a crash cushion; and a pair of wheels connected to said casing.